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PUBLIC HEALTH ASSESSMENTTroy Mills Landfill
Troy, Cheshire County, New Hampshire

EPA ID No. GAD980559413
October 28, 2004

Prepared by:

Bureau of Environmental and Occupational Health
New Hampshire Department of Environmental Services
Under a Cooperative Agreement with
Agency for Toxic Substances and Disease Registry




I. Purpose

On May 1, 2003, the U.S. Environmental Protection Agency (EPA) proposed the Troy Mills Landfill Site for the National Priorities List (NPL). Under 42 U.S.C. 9604, the Agency for Toxic Substances and Disease Registry (ATSDR) must perform a public health assessment (PHA) for all sites proposed for the NPL within 1 year of the date of listing. A PHA is a triage tool used by public health agencies to determine if any actions are needed to protect the community surrounding the hazardous waste site, and to determine if follow-up health activities (e.g., health studies, medical surveillance) should be done. To achieve this goal, this assessment contains three types of evaluations:
  1. the identification of pathways of exposure to site contaminants and an evaluation of their public health implications,
  2. a discussion of relevant and available health outcome data, and
  3. an evaluation of specific community health concerns about the site.
The New Hampshire Department of Environmental Services, Bureau of Environmental and Occupational Health (BEOH) is preparing this PHA under a cooperative agreement with ATSDR.

II. Background and Statement of Issues

A. Site Description and History

The Troy Mills Landfill (TML) is located in a predominantly undeveloped woodlands area about 1.5 miles south of the town center in Troy, New Hampshire (Figure 1). The approximately 10-acre TML is located in the southeastern portion of a 270-acre land parcel, which is owned by Troy Mills, Inc. The property is bordered to the north by an intermittent stream; to the east by a former railroad bed (currently utilized as a walking, all terrain vehicle and snowmobile trail); to the south by the eastern branch of Rockwood Brook; and to the west by a gravel access road, a wetlands area and Rockwood Brook. Rockwood Brook flows in a northerly direction for about 1.0 mile to where it enters Sand Dam Pond and Sand Dam Pond beach, a town recreational area (Figure 2) [1].

Before 1967, the TML was reportedly undeveloped. Beginning in 1967, Troy Mills, a manufacturer of synthetic fabrics [2], began using the site to dispose of 55-gallon drums of waste liquids and sludge. The drummed wastes consisted primarily of plasticizers and Varsol, a petroleum-based solvent, also known as Stoddard solvent or mineral spirits. Other wastes disposed at the landfill included pigments and tank residues of vinyl resins and top-coating products [3]. The waste drums were disposed in a 2-acre section of the landfill known as the drum disposal area [1]. On average, an estimated 15-20 drums of waste were disposed in this area per week. Many of the buried drums were dumped from trucks into trenches and reportedly compacted under the weight of heavy equipment [3]. Many of the buried drums were reportedly crushed or partially crushed in the process. Test pits conducted in the drum disposal area by EPA in September 2002 revealed that about two-thirds of the uncovered drums still contained liquids or sludges. The total number of waste drums disposed at the site has been estimated to be between 6,000 and 10,000 [4]. In addition to the drummed wastes, solid wastes such as scrap fabric, metal strapping, and fiberboard drums were also disposed in the TML, primarily in the remaining 8-acre section [3].

Following an inspection of the TML in 1978, the New Hampshire Bureau of Solid Waste Management (NH SWM) required Troy Mills to apply for a permit to operate a sanitary landfill [5]. The continued disposal of drummed chemical wastes at this location was disallowed at that time. Troy Mills was subsequently authorized to dispose of limited solid waste items (waste fabrics and damaged, nonrecyclable, empty 55-gallon drums) in the TML. These solid wastes were disposed in the remaining 8-acre portion of the TML [6]. In 2001, after Troy Mills filed for bankruptcy protection, the TML ceased operations on direction from the New Hampshire Department of Environmental Services (DES).

Before 1980, oily, orange-colored leachate was discovered on several occasions in drainage ditches located between the landfill area and the gravel access road. The leachate was observed to flow and spread out within the wetland area to the west of the access road [1].

Between 1980 and 2001, a number of environmental investigations of the TML property were conducted to characterize the nature and extent of contamination at the site. The EPA Final Expanded Site Inspection Report for Troy Mills Landfill, Troy, New Hampshire, dated January 21, 2003, provides a detailed discussion of the environmental investigations and regulatory actions undertaken during this time. Some of the findings of the 1980-2001 investigations include the following:
  • An estimated 6,000-10,000 waste drums were disposed in the 2-acre drum disposal area of the 10-acre TML between 1967 and 1978.
  • An indeterminate number of waste drums disposed at the TML are suspected of containing liquid and sludge wastes, consisting primarily of plasticizers and Varsol.
  • Solid wastes in the form of discarded synthetic fabrics and other materials were disposed in the remaining 8-acre portion of the TML.
  • Groundwater in the TML area has been contaminated by a number of chemical contaminants, but the direction of groundwater flow is away from inhabited areas. Groundwater near the TML is not being used as a source of water supply.
  • Leachate from the TML has migrated to the wetland area to the west of the TML and has caused observable orange staining of the wetland soils.
  • Migration of contaminants through leachate appears to be limited to the wetland area and the section of Rockwood Brook directly adjacent to the landfill.
  • Surface water in Rockwood Brook as it leaves the TML area has not been significantly affected by contaminants released from the TML. Contaminants of concern have not been detected in Sand Dam Pond (Figure 3).
In 1985, DES and Troy Mills, Inc. entered into a consent order that required remedial work at the landfill [7]. In 1992, Troy Mills submitted a feasibility study for TML that included a proposed remedy for capping the drum disposal area, installing additional monitoring wells, and implementing a contingency groundwater recovery and treatment system [1]. In early 2000, DES approved a containment remedy for the drum disposal area of the TML that was a modified version of the capping-based remedial action that had been proposed earlier. Later in the year, Troy Mills requested and received DES approval to temporarily defer implementation of the containment remedy because of unfavorable corporate financial and market conditions. DES approved this deferral in light of the TML's remote location and because monitoring data did not suggest an imminent and substantial threat to public health and the environment [8] [9].

In July 2001, DES asked EPA to initiate an Expanded Site Inspection (ESI) and Hazard Ranking System assessment in the event that Troy Mills became unable to undertake remediation of the site [1]. In October 2001, Troy Mills filed for Chapter 11 bankruptcy protection. In December 2001, as part of the ESI process, EPA collected soil and leachate samples from the TML. It also collected sediment and surface water samples along the surface water pathway to assess the potential downstream effects of contaminant migration from the TML [10]. At DES's direction, Troy Mills ceased disposal at the TML by the end of 2001. In February 2002, DES notified Troy Mills that the previously approved containment remedy (approved as a compromise because of the company's appeal related to its unfavorable financial condition) was no longer acceptable. This position was taken because the company could not afford to implement or operate the approved remedy. Accordingly, DES asked the EPA Site Remediation and Restoration Branch to consider a removal action at the site [9].

Following completion of the Hazard Ranking System assessment, the Troy Mills Landfill was proposed for listing to the National Priorities List (NPL) on April 30, 2003. In September 2003, EPA announced the beginning of construction of a temporary containment system for the landfill. The containment system consists of three separate interceptor trenches, each approximately 100 feet long. The system is intended to intercept floating contamination in groundwater before it can reach the wetlands area. The intercepted floating free product would be periodically removed for off-site disposal. The containment system has been constructed and a test period is underway [11].

B. Site Visit

On July 17, 2003, representatives of BEOH, EPA, ATSDR, and DES, accompanied local town officials on a site visit at the Troy Mills Landfill. The site visit included a tour of the landfill area where drums and solid wastes were buried, the wetlands area adjacent to the landfill, and access points used by possible trespassers. Approximately 3 hours were spent viewing the site and nearby areas of concern within the community. During the site visit, BEOH and the other agencies observed the following:
  • Unearthed fabric materials in the solid waste disposal area,
  • Tire tracks in the sand and dirt assumed to be from motorbikes or ATVs,
  • The flow of Rockwood Brook north to the site boundary,
  • Residential properties closest to the TML in Troy and Fitzwilliam,
  • Sand Dam Pond, one of the town's recreational areas,
C. Demographics and Land Use

According to the U.S. Census, the population of Troy in 2000 was 1,962 persons. Of particular interest are the populations of children and senior citizens. These groups are typically considered "sensitive" to the effects of environmental pollution. They may be affected by lower levels of contaminants, or they may have more serious reactions to these contaminants. Children younger than 5 years old and adults 65 years old and older account for 16.2% of the Troy population (Figure 4). The age distribution for the population is summarized in the following table.

Age (years) Persons Percentage
Under 5 years 117 6.0
5 to 9 years 143 7.3
10 to 14 years 172 8.8
15 to 19 years 143 7.3
20 to 24 years 108 5.5
25 to 34 years 255 13.0
35 to 44 years 353 18.0
45 to 54 years 290 14.8
55 to 59 years 107 5.5
60 to 64 years 74 3.8
65 to 74 years 105 5.4
75 to 84 years 79 4.0
85 years and over 16 0.8


D. DHHS Involvement

After the site was proposed for listing on the NPL on April 30, 2003, BEOH began work on a public health assessment (PHA). To date, BEOH staff have performed a site visit and conducted outreach activities with the nearby community. Highlights of BEOH involvement are provided below:
  • July 17, 2003-BEOH staff visited the site with ATSDR, DES, EPA, Troy selectmen and environmental consultants to observed conditions of the site.
  • September 23, 2003-BEOH held a public availability session and distributed an educational needs assessment survey to residents near the site. The objective of the needs assessment survey was to gather community health concerns and questions regarding the site so that these could be addressed in the PHA. Residents of the community were provided the opportunity to meet with BEOH staff, in a confidential setting, to discuss their personal health concerns and questions regarding the Troy Mills Landfill.
  • October 1, 2003-An article was published in the Troy Town News to explain the purpose of the Educational Needs Assessment that individuals would be receiving in the mail in early November.
  • November 4, 2003-BEOH's health promotion advisor met with Troy selectmen to distribute posters, provide the post office with a mass mailing, and place drop boxes throughout Troy for the easy retrieval of the Educational Needs Assessment.
  • November 6, 2003-BEOH Educational Needs Assessment surveys were sent out as a mass mailing by the Troy Post Office.
  • November 2003-An article was placed in the Troy Town News to remind residents of the purpose of the Educational Needs Assessment including information on when and how to return the information to BEOH.
  • December 2003 - An article in the Troy Town News thanked the town selectmen for their assistance and survey respondents for their participation in the Educational Needs Assessment.
E. Quality Assurance/Quality Control (QA/QC)

In preparing this document, BEOH relied on the information provided in the referenced documents. Only data collected using appropriate sampling and laboratory methods were considered in this analysis. Data with demonstrated QA/QC problems were excluded from summary tables or exposure calculations unless they provided unique and relevant information. BEOH has confidence in the data for the site because certified laboratories performed the analyses. Measurements of exposure point concentrations were taken directly from laboratory data sheets to avoid transcription errors.

III. Discussion

A. Assessment Methodology

To determine whether area residents are exposed to contaminants from the site, it is necessary to evaluate the environmental and human components that lead to human exposure (pathways analysis). This pathways analysis consists of five elements:
  1. a source of contamination,
  2. transport of contaminants through an environmental medium,
  3. a point of human exposure,
  4. a route of human exposure, and
  5. a receptor population.
Exposure pathways can be classified into three groups:
  1. Completed pathways-those in which human exposure to contaminants is reasonably likely to have occurred, is occurring, or is likely to occur in the future;
  2. Potential pathways-those in which at least one of the five exposure elements is missing; and,
  3. Eliminated pathways-those that can be eliminated from further analysis because one of the five elements is missing and will never be present, or in which no contaminants of concern can be identified.
After the pathways are designated as completed, potential, or eliminated, the next step is to obtain representative environmental monitoring data for the site of concern and to compile a list of site-related contaminants. This list of contaminants is compared to health-based comparison values (HCVs) to identify those contaminants that do not have a realistic possibility of causing adverse health effects. These comparison values are conservative, because they include ample safety factors that account for the most sensitive populations. Typically, if a contaminant is never found at levels greater than its comparison value, it is reasonable to conclude that the contaminant does not represent a public health concern. No further evaluation is needed for contaminants that do not exceed their respective HCVs. If, however, a contaminant is found at levels greater than its HCV, the pollutant is designated as a contaminant of concern and it needs to be further examined. Because HCVs are based on conservative assumptions, the presence of contaminant concentrations greater than a HCV does not necessarily mean that adverse health effects will result for those individuals who are exposed to the contaminants. (More information on comparison values can be found in Appendix D.)

For chemical contaminants designated as contaminants of concern, the next step is to evaluate site-specific conditions to determine what exposure scenario is realistic for a given exposure pathway. The exposure scenario makes it possible to determine a dose and compare this dose to scientific studies to determine whether the extent of exposure indicates a public health hazard.

B. Environmental Contamination

The following represents a brief overview of the chemical contaminants identified in different environmental media at the TML.

1. Drum Disposal Area

Analytical results of waste samples and subsoil samples collected in the drum disposal area between 1981 and September 2002 have indicated the presence of a number of volatile organic compounds (VOCs). Those include benzene, methylcyclohexane, toluenes, xylenes, 1,1,1-trichloroethane (1,1,1-TCA), trichloroethylene (TCE), methylene chloride, and vinyl chloride; semivolatile organic compounds (SVOCs) including napthalene, 2-methylnapthalene, pentachlorophenol, diethylphthalate, di(2-ethylhexyl) phthalate (DEHP), di-n-butyl phthalate, benzyl butyl-phthalate, and di-n-octyl phthalate; and inorganic elements, including aluminum, antimony, cadmium, chromium, copper, iron, lead, manganese, nickel, selenium, sodium, and zinc [1].

Contaminants detected in subsurface soil and source samples at concentrations exceeding the DES upper concentration limits for soils in New Hampshire include toluene (maximum detected concentration of 300 ppm in 1983) and DEHP (maximum detected concentration of 69,000 ppm in 1983 and 13,000 ppm in 2002) [1].

2. Groundwater

Groundwater in the overburden and bedrock beneath the drum disposal area flows west and northwest, discharging to Rockwood Brook. Analytical results of groundwater samples collected from the overburden groundwater between 1982 and November 2001 indicated the presence of a number of VOCs, SVOCs, and inorganic elements. Contaminants detected in the past at concentrations above DES ambient groundwater quality standards include acetone, carbon disulfide, several chlorinated VOCs, methyl ethyl ketone, toluene, DEHP, napthalene, cadmium, chromium, and lead.

Groundwater sampling data have shown a decrease in contaminant level concentrations for several contaminants over the approximate 20-year sampling period (Table 1) [1]. A floating product layer of light nonaqueous phase liquid (LNAPL) that contained DEHP, methylene chloride, naphthalene, and chromium had been discovered in groundwater near the drum disposal area. In December 2001, EPA's Superfund Technical Assessment and Response Team (START) collected a sample from the LNAPL layer at a location between the drum disposal area and the access road. This sample showed elevated concentrations of DEHP (250,000 ppm), di-n-octyl phthalate (12,000 ppm), and other contaminants associated with the site (Table 2). Given the distance and direction of known drinking water supply wells, no effects to nearby drinking water sources are known or expected [2]. Chemical analysis results indicate that contaminants have been released from TML and that contaminated groundwater has migrated to the wetlands area closest to TML.

3. Surface Water

Surface water runoff from the solid waste landfill area flows west toward Rockwood Brook, located 30-50 yards away (Figure 2). Surface water runoff from the drum disposal area flows southwest to the eastern branch of Rockwood Brook. Contaminated groundwater flowing from beneath the drum disposal area discharges as landfill leachate into drainage ditches located between the landfill and the gravel access road. Leachate in the southernmost drainage ditch then flows through a culvert under the access road to the wetland area west of the landfill [1]. Surface water samples collected between 1987 and November 2001 have detected low levels of VOCs, SVOCs, and inorganics in this wetland area [1]. More recent sampling conducted in this wetland area by START in December 2001 has again detected low levels of these contaminants (Table 3). During 2001, DES collected surface water and sediment samples in Sand Dam Pond (Figure 3). No VOCs, SVOCs, or inorganics were detected in the surface water sample collected at this time [12]. The Town of Troy conducted its own sampling of surface water at Sand Dam Pond during 2002 [13]. No contaminants were detected at levels above health comparison values.

4. Sediment Samples

As indicated in the previous section, surface water runoff from the drum disposal area and solid waste area flows toward Rockwood Brook. Contaminated groundwater discharges as landfill leachate into a drainage area west of the landfill and, from there, to the adjacent wetland area through a culvert under the gravel access road. Sediment samples collected in Rockwood Brook in 1995 indicated the presence of low levels of several inorganic compounds and one pesticide, methoxychlor (2.3 ppb). Background sampling data collected as part of this effort were inconclusive. They did not resolve whether these contaminant concentrations are attributable to the TML, other potential off-site sources, or tributaries discharging to Rockwood Brook [1].

In December 2001, START collected seven sediment samples in the wetland area bordering the TML to document the release of contaminants from the landfill. Analytical results of these samples indicated elevated levels of two VOCs, cis-1,2-dichloroethene (42 ppb), and toluene (21 ppb); one SVOC, DEHP (2.3 ppm); and several inorganics, including manganese (5,758 ppm). These contaminant concentrations are below a level of health concern (Table 4).

DES collected sediment samples in Sand Dam Pond during 2001. No VOCs or SVOCs were detected. Low concentrations of chromium (16 ppm) and lead (42 ppm) were found, but DES did not attribute these inorganics to contaminant migration from the site [12]. The concentrations are within the ranges considered to be "background" levels for these substances in New Hampshire soils [14]. DES has stated that the presence of these contaminants could represent normal background levels or may be attributable to other sources [12].

C. Analysis of Exposure Pathways

Environmental contamination cannot affect a person's health unless he or she comes into physical contact with it. Moreover, human contact with environmental contamination is only possible when a completed exposure pathway exists. A completed exposure pathway exists when all of the following five elements are present:
  1. a source of contamination,
  2. transport through an environmental medium,
  3. a point of exposure,
  4. a route of human exposure, and
  5. an exposed population.
For the Troy Mills Landfill, the various exposure pathways are discussed in the following sections.



Table 1. Completed Exposure Pathways Recreational/Trespassers Pathway

Name Source Environmental Transport and Medium Exposure Point Exposure Route Exposed Population Time Frame
Recreational/Trespassing (TML) Landfill Wastes Leachate Sediments/ Surface water Ingestion
Dermal
Recreators/ Trespassers Past
Present
Future


The TML is located in an area of mostly undeveloped woodlands. To the east of the site is a former railroad bed now used as a walking, all terrain vehicle (ATV), and snowmobile trail. A gravel access road runs adjacent to the wetlands area, between the drum disposal area and Rockwood Brook. Although a gate on the road is kept barred, the site itself is not fenced and is accessible to trespassers. A completed exposure pathway exists for individuals who enter this area, including hikers and children who play there. The elements of this pathway are identified in the above table. These individuals may have come into contact with contaminants in the drainage ditch and wetlands sediments. It is unlikely, however, given the limited opportunities for exposure and the generally low levels of contaminants detected in these media, that actual exposures would cause adverse health effects.



Table 2.

Potential Exposure Pathways Air Pathway
Name Source Environmental Transport and Medium Exposure Point Exposure Route Exposed Population Time Frame
Air Landfill Wastes Soil Vapor Ambient Air Inhalation Trespassers to the TML Past
Present
Future


The area where the TML is located is remote from any habitable areas. As indicated above, although the TML has been posted, it is possible for individuals to access the area for walking, snowmobiling, and other types of recreational activities. Some residents have expressed a concern about the possibility of breathing vapors from the contaminated waste materials in the drum disposal area while hiking or conducting other recreational activities near the site. During the ESI investigations in 2001, ambient air was screened by START using photo ionization detectors and flame ionization detectors. No sustained elevated concentrations of VOCs in ambient air were detected during this time. However, START did detect elevated concentrations of VOCs in the headspace of a monitoring well located adjacent to the drum disposal area and directly above several sample locations in the TML (1).

Although there is no indication that trespassers or other individuals entering the TML are being exposed to elevated levels of VOCs. The inhalation of vapors in the drum disposal area of the TML constitutes a potential exposure pathway.

3. Eliminated Exposure Pathways
Groundwater beneath the drum disposal area has been contaminated by a number of chemicals originating from the site. The direction of groundwater flow is westward, away from any inhabited areas located near the TML. Local residents are not using this contaminated groundwater as a source of drinking water, so they are not being exposed to contaminants through their drinking water. It is also extremely unlikely that contaminated groundwater would ever be allowed to be used as a drinking water supply. Consequently, this pathway has been eliminated and will not be considered further in this assessment.

D. Public Health Implications of Exposure

Environmental investigations have documented the movement of contamination from the drum disposal area to the wetlands area adjacent to, and immediately west of, the TML. Exposure to contaminants in surface water and sediments is possible, therefore, for individuals who trespass in this area or use it for recreational activities. The sampling data available has shown low levels of contaminants [primarily di(2-ethylhexyl) phthalate, manganese, and cis-1,2-dichloroethene] in surface water in this area.

Di(2-ethylhexyl) phthalate, also known as bis(2-ethylhexyl) phthalate or DEHP, is a synthetic chemical that is commonly added to plastics to make them flexible. Because of its many applications and uses in commercial products, DEHP is commonly found in the environment. When present in soil and water, it breaks down readily through microbial action. There is little available information on the human health effects associated with exposure to DEHP at concentrations normally found in the environment. Laboratory test animals exposed to high levels of DEHP have suffered liver damage. Humans absorb and break down DEHP differently than laboratory animals. It is not clear that humans would experience the same problems noted in these laboratory studies. The EPA has classified DEHP as a probable human carcinogen (capable of causing cancer) [15].

DEHP has been found in surface water near the site at a level exceeding its health comparison value. Given the limited frequency of detection, low concentration, and limited opportunities for contact with this contaminant in surface water, exposure to DEHP is not likely to result in adverse health effects.

Cis-1, 2-dichloroethene is used in the manufacture of solvents and is present in many chemical mixtures. There is little information on the long-term health effects for humans associated with exposure to low levels of this compound in water or other environmental media. Cis-1, 2-dichloroethene is not considered to be a human carcinogen [16]. At the low concentrations detected (maximum detected concentration = 200 ppb) and the limited frequency that people might come into contact with this contaminant in this medium, exposure to cis-1, 2-dichloroethene in surface water near the TML is unlikely to result in any adverse health effects.

Manganese. Very little information is available about the human health effects associated with ingestion of manganese. Motor coordination problems have been reported for children who were exposed to above-average concentrations of manganese in food and water. There were flaws in the studies that reported these results, however. It is not clear if the motor coordination problems were the result of consuming manganese or if other factors were involved [17].

Manganese was detected in surface water near the TML site at a concentration exceeding its respective health comparison value, as well as, the State of New Hampshire Drinking Water Standard. Surface water near the TML is not used as a source of drinking water. Given the limited frequency of exposure and the unlikelihood that anyone would accidentally ingest large quantities of surface water, exposure to manganese is not expected to result in adverse health effects.


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