PUBLIC HEALTH ASSESSMENT
EASTERN SURPLUS COMPANY SITE
MEDDYBEMPS, WASHINGTON COUNTY, MAINE
The Agency for Toxic Substances and Disease Registry (ATSDR) first became involved in the Eastern Surplus Company (Eastern Surplus) site in the 1980s when the Maine Department of Environmental Protection (MEDEP) started investigating the site. The Eastern Surplus site is a 5-acre site located in Meddybemps, Maine. From 1946 through 1976, the site was used for storing and selling military surplus goods and other refuse. Because of past activities at the site and the potential for site-related contaminants to impact Meddybemps Lake and Dennys River, the site was placed on the U.S. Environmental Protection Agency's (EPA) National Priorities List (NPL) in June 1996.
Since site investigations began in the 1980s, groundwater, private wells, surface soil, surface water, sediment, ambient air, and fish tissue were sampled. Sampling results indicate that on-site soils were contaminated with various organic compounds, polychlorinated biphenyls (PCBs), and metals that migrated into the underlying groundwater, surface water and sediments, and possibly biota .
MEDEP, EPA, the U.S. Army Corps of Engineers (USACE), and the Department of Defense (DOD) completed a number of removal and cleanup actions at the site. These actions included removing hazardous materials (e.g., drummed chemicals and stained soil) and physical hazards (e.g., decayed gas cylinders and debris), excavating contaminated soil, installing a groundwater pump-and-treat system, and conducting long-term monitoring to verify the effectiveness of the remedial actions.
A small year-round residential community lives in Meddybemps, Maine. This population triples in the summer when seasonal residents occupy homes along the lake. The Passamaquoddy Tribe lives downstream of the site, approximately 15 miles to the southeast, and reported that they formerly used the area for gathering medicinal plants and subsistence hunting and fishing.
- Drinking water from private wells and Meddybemps Lake,
- Trespassing and contacting surface soil on site,
- Using Meddybemps Lake and Dennys River for recreation,
- Inhaling airborne contaminants from the site, and
- Gathering plants, hunting animals, or fishing near the site.
Community members were concerned about potential health problems arising from exposure to contaminants in groundwater, surface soil, and air. They were also concerned that contaminants in surface soil and sediment would impact the fish in Meddybemps Lake. Members of the Passamaquoddy Tribe questioned whether unique health problems might arise from using culturally significant plants and animals from the site. ATSDR evaluated the available data to determine whether health effects or illnesses could result from exposures to contaminants in groundwater, surface soil, surface water, sediment, air, and site biota (animals and plants).
Because critical data are missing to enable ATSDR to draw conclusions about all public health issues at the site, ATSDR characterizes the site as an Indeterminate Public Health Hazard. (See Appendix E for definitions of the different health classifications).
ATSDR classifies current and future exposures at the site as posing an indeterminate public health hazard. This classification is based on the fact that there were limited fish data and no plant data to address community health concerns and to make a public health call related to these potential exposure pathways. Available data indicate that elevated levels of PCBs, pesticides, and metals (specifically mercury) may be present at concentrations above ATSDR's health-based comparison values (CVs) in fish and mussels from Meddybemps Lake and Dennys River. Area residents and members of the Passamaquoddy Tribe expressed concerns that site-related contaminants may have impacted the fish population in the area. To address this data gap, ATSDR recommends additional fish and mussel samples be collected from Meddybemps Lake and Dennys River. EPA and the Passamaquoddy Tribe agreed to conduct a joint site visit to identify plants used by the tribe. ATSDR recommends that area residents and recreational users of area water bodies continue to follow the State of Maine fish consumption advisories that are based on state-wide mercury contamination concerns and PCB contamination concerns for Dennys River.
Members of the Meddybemps community and Passamaquoddy Tribe also expressed concerns about contact with contaminants in groundwater, surface soil, surface water, sediments, air, and animals. Available data indicate that current and future exposures with groundwater, surface soil, surface water, sediment, air, and biota would not pose a public health hazard. The groundwater data identified volatile organic compounds (VOCs)--mainly tetrachloroethylene (PCE) and trichloroethylene (TCE)--semivolatile organic compounds (SVOCs), PCBs, and metals above ATSDR's health-based CVs. Surface soil data contained levels of VOCs, SVOCs, pesticides, PCBs, and metals above their CVs. Surface water and sediment data found levels of VOCs, SVOCs, pesticides, PCBs, and/or metals above their CVs. No data are available to evaluate contaminants that may have collected in animals.
Although contaminants were found above CVs in groundwater, surface soil, surface water, and sediment, exposures to these contaminants are not expected to cause illness or adverse health effects. ATSDR develops health-based CVs assuming a person drinks water containing contamination daily or contacts soil or sediment daily. Nobody uses on-site groundwater for drinking water, however, several nearby residences have private wells and summer residents may use surface water for drinking water. As such, ATSDR evaluated contaminant concentrations assuming a person drank 2 liters of water (the equivalent of a plastic 2 liter soda bottle) every day for many years. Even at these exposure levels, ATSDR concluded that no adverse health effects would result from use of private wells or surface water for drinking water.
In assessing exposures to surface soil or sediment, a person would need to eat 100 milligrams (mg) (the equivalent of a restaurant sugar packet) of soil or sediment every day for many years to increase their chance of experiencing adverse health effects. Even at this exposure level, illness or adverse health effects are only possible, and not guaranteed, because ATSDR sets its CVs at levels much lower than levels shown to result in adverse effects in reported studies. Daily exposure to surface soil and sediment is not expected because nobody lives at the site and Maine's climate constraints make it seem unlikely that someone would access the site on a daily basis. Adverse health effects, therefore, are not expected from exposures at the site.
No data were available to characterize contaminant levels in animals, however, no adverse health effects are expected because the site is currently not used for hunting. In evaluating animal exposures to site contaminants, ATSDR believes that no future health effects are expected because site remediation has reduced the site contaminant concentrations. Animals exposed to the contaminant concentrations would not collect contaminants in their bodies at concentrations that could be harmful to those consuming meat from hunted animals.
ATSDR characterized past exposures at the Eastern Surplus site as an indeterminate public health hazard because no data are available to enable ATSDR to evaluate possible exposures to contaminants in surface soil, air, and biota (plants and animals) before site remediation began in the 1980s and 1990s.
To assess past exposures to contaminants in groundwater, surface water, and sediment, available site data were considered representative of past exposures because no actions were taken to remove contaminants from these media before sampling was conducted. Using these data, ATSDR determined that no health effects were expected from possible past exposures to contaminants in groundwater, surface water, or sediment. As discussed previously, the contaminant concentrations detected in private wells and surface water, were below levels likely to cause adverse health effects, even assuming a person drank 2 liters of water every day for many years. Exposure to sediment is not expected to result in adverse health effects because exposures would be limited by the climate constraints of Maine.
ATSDR also evaluated physical hazards that may result in injury at the site. A dilapidated hydroelectric power unit straddles the Dennys River in the southern portion of the site. ATSDR recommends that this unit be demolished or access to the area restricted to prevent trespassing and potential injury.
In this public health assessment, the Agency for Toxic Substances and Disease Registry (ATSDR) evaluated the public health significance of the Eastern Surplus Company (Eastern Surplus) site in Meddybemps, Maine. The Superfund law (the Comprehensive Environmental Response, Compensation, and Liability Act of 1980, as amended by the Superfund Amendments and Reauthorization Act of 1986) requires ATSDR to conduct public health assessments of sites placed on the National Priorities List (NPL).
In conducting the public health assessment, ATSDR identified the following community health concerns:
- The potential for health problems from; 1) using groundwater as a drinking water supply, as well as other household uses, such as showering; 2) children coming in contact with site contamination while playing at the site prior to site remedial actions; 3) breathing airborne contaminants from the site.
- The potential for sediment, surface water, and fish in Meddybemps Lake to become contaminated because of the site.
- The potential for unique health problems in members of the Passamaquoddy Tribe from using culturally significant plants and animals for consumption, medicinal and religious practices. Tribe members specifically mentioned deer, moose, muskrat, and Atlantic salmon as animals important to the tribe.
To address community concerns and identify other potential exposure pathways, ATSDR evaluated site conditions and available environmental data to determine whether adverse health effects could occur. ATSDR considered whether actions are needed to reduce, prevent, or further investigate the possibility for exposures to site-related contaminants to result in adverse health effects. Most of the data collected at the site, and presented in this public health assessment, are from the remedial investigation (RI) completed in 1999.
ATSDR released this public health assessment for initial and public comment release in July, 2002. The public comment period ended on September 30, 2002. No comments were received during this public comment period; therefore, this public health assessment is being released as the final version of this document.
ATSDR will evaluate new data as they become available.
The Eastern Surplus site is located in Meddybemps, Washington County, Maine (Appendix A, Figure 1), approximately 70 miles northeast of Bangor, Maine. This 5-acre site is a former junkyard that was abandoned in the 1970s (1). In 1999, a court agreement, called a Consent Decree, required transfer of site ownership to the State of Maine (2). A hydroelectric unit that straddles Dennys River was not included in the property transfer and remains under private ownership. Meddybemps Lake is located to the north, Mill Pond and Upper Dennys River are to the east, Route 191 is to the south, and private property and Stone Road are to the west of the site.
Currently, access to the site is restricted by a fence and the site is cleared, with little vegetation. No access restrictions are in place where the site abuts Meddybemps Lake or Dennys River. In 1998, the U.S. Army Corps of Engineers (USACE) demolished two on-site buildings (a wood frame house and a concrete store/office building). The only remaining structure is an abandoned and deteriorating generator building associated with a former hydroelectric station; the building straddles Dennys River at the southern site boundary. There are no fences or other means to restrict access to this structure from the eastern bank of Dennys River (Appendix A, Figure 2) .
The nearest residences are found approximately 150 feet east of the site boundary, across Dennys River. There are also residences located on the same side of the river as the site; the nearest home is approximately 1/4 mile north of the site.
The site was farmland until October 1946, when it was purchased for use as a materials and equipment storage site for the Eastern Surplus Company. By 1973, the Eastern Surplus Company reportedly stopped using the site for receipt and storage of surplus and salvage materials. Many different military surplus goods and materials were reportedly stored on site over the years, including paints, primers, solvents (toluene, xylene, methanol, 1,1,1-trichloroethane), fungus inhibitor compounds (containing tetrachloroethylene [PCE] and paranitrophenol), mineral spirits, degreasers, lubricants, greases, transformers, capacitors, electrical components, munitions, calcium carbide, pesticides, coatings, acids (sulfuric, phosphoric, and hydrochloric), ether, compressed gas cylinders, and defunct vehicles. In addition, numerous transformers and capacitors filled with polychlorinated biphenyl (PCB) dielectric fluid were stored on site. Because of weathering and corrosion of containers these chemicals were released into the environment (1).
The site also supported a hydroelectric power unit along Dennys River at the southern site boundary. A military surplus business (store) was located in a building in the southeastern corner of the site. The hydroelectric power unit operated until 1966 and the store was open until 1976. A calcium carbide fire reportedly occurred in 1976 in the north-east quadrant of the site (1).
In 1985, the Maine Department of Environmental Protection (MEDEP) conducted a site inspection and found compressed gas cylinders, 55-gallon drums, a trailer full of calcium carbide, leaking electrical transformers, capacitors and switches, old ammunition, and various other containers with unknown contents stored on the site. In December 1985, MEDEP identified the site as an "Uncontrolled Release Site", initiated emergency remediation and removal measures, and installed a fence around the site to prevent access (1).
By May 1986, MEDEP had removed 4,650 gallons of waste oils, 2,400 gallons of PCBs, and 117 transformers; MEDEP requested federal assistance on the site. From 1986 to 1990, the U.S. Environmental Protection Agency (EPA) and the Department of Defense (DOD) conducted numerous sampling events and removal actions (1).
In June 1996, the site was placed on the National Priorities List (NPL). As a result, a remedial investigation/feasibility study (RI/FS) began at the site. As part of the RI/FS, samples were collected from ambient air, groundwater, private wells, surface soil, surface water, sediment, and fish tissue. As part of the RI/FS process, DOD also removed unexploded ordnance from the site in 1998. The final RI report was released in 1999 (1). Appendix C presents a time line of operational and regulatory activities at the site.
Based on results from site investigations, EPA is conducting remediation in two phases--short-term and long-term remediation. The short-term remediation plans were completed; the contaminated soils were removed from the site and transported off-site for disposal in the summer 1999, and a groundwater pump-and-treat system was installed in 1999. The groundwater pump-and-treat system was installed to control contaminant migration and to reduce contaminant levels in the two volatile organic compound (VOC) plumes present on site. The system began operating in January 2000, and is designed to withdraw contaminated groundwater from the aquifer through extraction wells, treat the water by removing contaminants, and then place the clean water back into the aquifer (2).
The long-term remediation consists of groundwater migration control and restoration and a long-term monitoring program with the intent to have groundwater at the site meet federal and state drinking water standards. EPA will sample groundwater and surface water twice a year for the first 5 years, then once a year until groundwater cleanup levels are attained to ensure that the pump-and-treat system is working to remediate groundwater contamination beneath the site. Groundwater sampling will also include sampling two private wells near the site. Because the groundwater discharges to surface water, EPA will also collect surface water and sediment samples for the first 5 years to assess the success of the pump-and-treat system. If remedial cleanup goals are not met within 10 years, MEDEP will become responsible for the long term operation, maintenance, and monitoring of the pump-and-treat system. As part of the long-term remediation, EPA is also investigating in-situ oxidation as an additional remedial option. The details of the long-term monitoring program will be finalized after testing in-situ oxidation treatments is completed and operation of the pump-and-treat system is optimized (2, 3, 18). The components of the long-term remediation program are detailed in the Record of Decision (ROD) for the site. In September 2000, EPA signed the ROD, which outlines the required remedial actions at the site (4). With the signing of the ROD, EPA begins the year-long transition from the early cleanup actions to the long-term remediation phase (18).
In addition to studies of chemical contamination at the site, archaeological and cultural investigations continue as well. In September 2000, EPA, MEDEP, and the Passamaquoddy Tribe held an open house to provide the community with information about the cleanup and archaeological work at the site. At this event, the Passamaquoddy Tribe named the archaeological portion of the site "Ntolonapemk" (meaning "Our Relative's Place"), which provides an indication of the cultural significance of the site. In agreement with a Memorandum of Agreement (signed by EPA, the State of Maine Historic Preservation Commission, the National Advisory Council on Historic Preservation, and the Passamaquoddy Tribe), EPA has completed the first phase of the mitigation requirements of the archaeological investigations. Future archaeological investigation activities include assessing sediments; cataloging artifacts; testing soil, sediment, plant, and animal remains; analyzing data; preparing museum exhibits; and completing curation of project materials and transfer to a designated facility. The University of Maine has been contracted to initiate a cultural study and to inventory the cultural materials recovered from the site (18).
The 1990 U.S. Bureau of Census estimates that approximately 35,300 individuals live in Washington County (5), 142 people live in Meddybemps, Maine, and 24 live within a 1-mile radius of the site. Figure 3 (Appendix A) and Table 1 (Appendix B) provide additional information about the year-round population surrounding the site. During the summer season, the population of Meddybemps approximately triples (1). This summer population is not included in the demographic information provided in Figure 3 and Table 1.
Residential homes near the site are located along the Meddybemps Lake and Dennys River shorelines. The nearest residence is located on the eastern bank of Dennys River, opposite the site, approximately 150 feet east of the site boundary. The nearest home on the western bank of Dennys River is approximately 1/4 mile north of the site. Some commercial properties are located within 0.1 mile of the site and some land within a 1 mile radius of the site is used for agriculture (1).
The State of Maine designated Meddybemps Lake suitable as a drinking water supply with disinfection, as well as suitable for recreation, fishing, industrial processes, hydroelectric power generation, and as a habitat for fish. During the summer, people use the lake for fishing, boating, and swimming. During the 1996 RI, EPA observed local residents fishing from a bridge over Dennys River (1).
The Passamaquoddy Tribe formerly used the site for subsistence hunting and fishing, but stopped in the late 1970s because of concerns about pollution (6). The tribe is also interested in the site because numerous artifacts were uncovered during excavation activities at the site. Most of the members of the Passamaquoddy Tribe that used Meddybemps Lake and Dennys River for hunting, fishing, and gathering live at Pleasant Point, approximately 15 miles southeast of the site (7).
In 1986, ATSDR conducted a site visit and subsequently classified as a public health hazard based on the presence of hazardous materials (e.g., stored chemicals and gases) and physical hazards (e.g., debris and abandoned structures) (8). ATSDR's public health conclusion classifications are defined in Appendix E of this document.
In the 1980s, EPA and DOD conducted removal actions at the site to mitigate public health hazards. As part of these actions, cylinders of gas that could not safely be removed from the site were exploded and burned in place. ATSDR provided EPA and DOD health information and air dispersion models for the release of gases during these activities. People living near the site were evacuated from the area before any explosions or burning activities began (8).
In August 1996, ATSDR conducted another site visit because the site was added to the NPL. In 1997, ATSDR prepared a Revised Site Review and Update report based on information gathered during the site visit. That document provided an update of actions taken at the site since ATSDR's 1986 site visit and changed the 1986 site classification from public health hazard to indeterminate public health hazard. MEDEP, EPA, and DOD conducted numerous removal actions between ATSDR's 1986 and 1996 site visits to remove any explosive and/or extremely hazardous materials from the site. As such, any immediate public health hazards were removed from the site. Remaining contamination, however, had not been fully characterized; therefore, no conclusions could be made about potential health hazards associated with exposures to any remaining site contamination (8).
Since the 1997 report was released, ATSDR has worked with EPA and members of the Passamaquoddy Tribe to further understand and address environmental health and tribal concerns associated with the site (9).
During the 1996 site visit, ATSDR identified community concerns associated with contamination at the site. In preparing this public health assessment, ATSDR contacted EPA and a representative of the Passamaquoddy Tribe and reviewed site documentation to identify additional concerns regarding the site. Following is a summary of potential concerns, which are addressed in the Discussion section of this public health assessment:
- The potential for health problems from using groundwater as a drinking water supply source, as well as for other household uses, such as showering.
- The potential for health problems from children playing at the site when contaminants were present.
- The potential for sediment, surface water, and fish in Meddybemps Lake to become contaminated because of the site.
- The potential for health effects from breathing airborne contaminants from the site.
- The potential for unique health problems in members of the Passamaquoddy Tribe from using culturally significant plants and animals for consumption, medicinal practices, and religious practices. Tribe members specifically mentioned deer, moose, muskrat, and Atlantic salmon as animals important to the tribe.
This public health assessment was released to the public for comment in July 2002. The comment period ended on September 30, 2002. No public comments were received during this period; therefore, this public health assessment is being released as final. ATSDR will continue to evaluate data for this site as they become available and will evaluate any data generated that will answer the community concerns listed above.
To evaluate community concerns and possible public health implications of contamination related to the site, ATSDR reviewed available environmental data for the site and the site vicinity. Section A of this discussion describes ATSDR methodologies, Section B presents ATSDR's evaluation of possible exposures associated with the site, Section C evaluates potential physical hazards associated with materials stored on the site, Section D discusses health outcome data, and Section E focuses on children's health.
The following sections contain evaluations of available environmental data for the site. ATSDR used established methodologies for determining how people may be exposed to site-related contaminants and evaluating what health effects, if any, can be associated with exposures to the contaminant concentrations in the different media. To make this determination, ATSDR identified exposure pathways, or the ways in which a contaminant may enter a person's body (ingestion, inhalation, or skin contact). If an exposure pathway was or is possible, the contaminant concentrations are evaluated to determine whether adverse health effects could occur. Potential exposures from groundwater, surface soil, surface water and sediment, air, and biota were evaluated and are summarized in Table 2 (Appendix B). For these media, Tables 3 through 11 (Appendix B) present the contaminants selected for further evaluation, the frequency of detection, the maximum detected concentration, and the sample location where the maximum detected concentration was found. Figures 4 through 8, Appendix A, show the sample locations for each medium.
ATSDR selects contaminants for further evaluation based on whether detected concentrations exceed health-based comparison values (CVs). CVs are conservative screening values with built-in safety factors to account for uncertainties and sensitive populations (e.g., children or the elderly). Although a concentration equal to or below the relevant CV may be considered safe, it does not necessarily follow that a contaminant that exceeds the CV is a health threat. If a contaminant exceeds the CV, a more detailed exposure analysis for that chemical is performed. It should be emphasized that regardless of the level of contamination, a public health hazard exists only if people come in contact with, or are otherwise exposed to, harmful levels of contaminated media. Appendix D provides more information about ATSDR's evaluation methods and Appendix E defines some of the terms used in this public health assessment.
Several contaminants were detected in on-site groundwater. However, no past or current exposure pathways were identified. People are not currently using on-site groundwater as a drinking water source and there is no documentation that past exposures occurred. Therefore, on-site groundwater presents no health threat. Groundwater on site is presently undergoing remediation through a pump-and-treat system to prevent off-site contaminant migration. Sampling of nearby private wells did not identify contaminants at levels associated with adverse health effects.
The site is underlain by course to fine outwash and glacial till overlying bedrock. The outwash and overburden material ranges in thickness from 0 feet in the south where rock outcrops are seen to 30 feet in the western portion of the site. The outwash material consists of layers of gravel, sand and gravel, sand, and sediments. The glacial till is a dense mixture of sand and gravel. The upper layers of the bedrock are weathered, broken, and contain joints and fractures (1).
Groundwater beneath the site appears to exist in two aquifers--one in the overburden and another in the bedrock. These two aquifers are hydraulically connected, but there is some indication that the bedrock aquifer is semi-confined and, thus, there is some degree of separation between the two aquifers. Movement of water between the aquifers and soil layers may occur through pathways (e.g., gravel layers) in the overburden and joints and fractures in the bedrock. The depth to groundwater ranges from 4 to 10 feet below ground surface (bgs) in the northern portion of the site, and from 12 to 20 feet bgs in the southern portion of the site. In general, groundwater in the overburden and bedrock aquifers flows to the southeast, toward Dennys River. The potential exists for groundwater in the bedrock aquifer to flow east under Dennys River (1).
On-site groundwater is not presently used. A residence in the northeastern portion of the site was abandoned in the 1970s and demolished in 1998. The source of water for this residence is unknown, however, no evidence of a drinking water well was found on site. Because the residence was located near the shore of Meddybemps Lake, it likely used the lake as a water supply. Because there is no evidence of a drinking water well on site, no past exposures to on-site groundwater were identified (3). On-site groundwater is presently undergoing remediation through in-situ oxidation treatments and a pump-and-treat system. EPA is also working with property owners to restrict future uses of groundwater by placing institutional controls, such as deed restrictions, that will include land and site use restrictions to prevent the future use of contaminated groundwater (2, 3, 4).
Meddybemps has no public drinking water supply, so all residents living near the site rely on private wells for their water supply (1). All but one of these wells are in the bedrock aquifer; the only exception is a shallow well that receives water from the overburden aquifer. Summer residents in Meddybemps reportedly use lake water for drinking, but none of the year-round residents are known to use lake water for drinking. No residences are reported to use Dennys River as a water supply. Between 1996 and 1998, EPA identified and sampled a total of 32 private wells located near the site--several of these wells were sampled on multiple occasions (Appendix A, Figure 4). In 1996, private wells were identified by canvassing the area surrounding the site (3). The closest drinking water well is located approximately 125 feet southeast of the site.
Groundwater Data Evaluation
As part of site investigations, extensive groundwater sampling has occurred since September 1996, including testing of a network of monitoring wells and of nearby private wells. Between September 1996 and June 1999, EPA sampled 36 monitoring wells for 179 chemicals (Appendix A, Figure 5). Sampling found VOCs, semi-volatile organic compounds (SVOCs), PCBs, and inorganics above CVs (Appendix B, Table 3). The highest concentrations of most chlorinated VOCs (chloromethane, 1,2-dichloroethene, methylene chloride, PCE, and vinyl chloride) were found in the northern portion of the site. The highest concentrations of aldrin, antimony, arsenic, and manganese were also found in the area of the northern plume. The highest concentrations of bis(2-ethylhexyl)phthalate were detected in the center of the site. PCBs were detected at their highest concentrations in a cluster in the southeast corner of the site (1).
Based on this data, EPA identified two VOC plumes: a northern and a southern plume. The highest detected contaminant levels were generally associated with the northern plume, found in the northeast quadrant of the site. The groundwater in the northern plume is believed to have been contaminated from soils containing high concentrations of VOCs and dense non-aqueous phase liquids (DNAPL). These contaminants are flowing to the southeast and may be discharging to Dennys River east of the site. The southern plume is located in the southeastern portion of the site. Contaminants in the southern VOC plume flowed to the south beyond the site boundary. Contaminants in this plume are also discharging to Dennys River (1).
In January 2000, EPA began operating a pump-and-treat system that draws contaminated water from both the northern and southern plumes for treatment and is designed to minimize contaminant migration, particularly discharge to the river. The goal of the system is for the water at the site to meet federal and state drinking water standards. Between the start of operations and fall 2000, EPA worked to optimize the operation of the treatment system and maximize contaminant removal. To this end, EPA is also investigating in-situ oxidation as an additional remedial option (2). A regular monitoring program for the pump-and-treat system has not been initiated. However, monitoring has been conducted on a weekly to monthly basis during the period of optimizing the treatment system. The details of the long-term monitoring program will be finalized after testing in-situ oxidation treatments is completed and operation of the pump-and-treat system is optimized (3). EPA is responsible for the first 10 years of operation and maintenance. If remediation is still required after 10 years, MEDEP will take responsibility for the long-term monitoring program until cleanup levels are attained (2).
Off-site groundwater monitoring well data contained the highest detected concentrations of the following contaminants: benzene (MW-1B and MW-16S), cadmium (MW-8S), carbazole (MW-1B), lead (MW-8S), naphthalene (MW-1B), toluene (MW-8B), total polynuclear aromatic hydrocarbons (PAHs) [MW-1B], vanadium (MW-11S), and zinc (MW-8S). The well locations can be found on Figure 5, Appendix A. These contaminants were found at concentrations slightly above their respective comparison values (CVs).
Residences in Meddybemps rely on private wells for their drinking water supply. Only summer residents are thought to use lake water as a drinking water supply. Although no private wells were located within either of the VOCs plumes, EPA sampled 32 private wells between September 1996 and June 1999, to determine if these wells were affected by site-related contamination (Appendix A, Figure 4). Private well samples were analyzed for 181 chemicals, including VOCs, SVOCs, pesticides, PCBs, and inorganics. PCE, bis(2-ethylhexyl)phthalate, arsenic, manganese, thallium, and zinc were detected above CVs in some private wells (Appendix B, Table 4).
PCE was detected three times, but only once above its CV. Bis(2-ethylhexyl)phthalate was detected above its CV in one well located east of the site across Meddybemps Lake. However, it was not detected in its duplicate sample. Bis(2-ethylhexyl)phthalate is used in laboratories during analyses. Because sample contamination with bis(2-ethylhexyl)phthalate can happen in the laboratory, and it was not found in another sample taken from the same well, its presence in the well could be attributed to the laboratory and is considered questionable. Arsenic concentrations exceeded CVs in five private wells near the site. The highest arsenic concentrations were detected southwest of the site. Manganese was detected above its CV in four samples collected from a single private well. Thallium was detected twice, but follow-up sampling of the wells did not detect thallium. Zinc was detected above its CV once, but further testing of this well did not detect zinc above the CV.
Public Health Implications
No past, current, or future public health hazards are associated with on-site groundwater contamination because there is no evidence that people used, are using, or are planning to use on-site groundwater for drinking or other purposes. No private drinking water wells were identified on site. To prevent future exposures, EPA is coordinating with the State of Maine to establish institutional controls, such as deed restrictions, that will include land and site use restrictions to prevent future use of groundwater at the site (2, 4). In addition, EPA is operating a pump-and-treat system and conducting in-situ oxidation treatments to remediate groundwater contamination. To date, water leaving the treatment system has met EPA's maximum contaminant levels (MCLs). A long-term monitoring program evaluating the effectiveness of site remediation activities will be established when testing in-situ oxidation treatments is completed and operation of the pump-and-treat system is optimized (3). The long-term monitoring will involve surface water and sediment sampling as well as groundwater and private well sampling. ATSDR will review data from the long-term monitoring program once monitoring begins.
The community expressed concern about potential health problems from using off-site groundwater as a drinking water supply, as well as other household uses, such as showering. No past, current, or future adverse health effects are expected from use of private wells for drinking water or other household uses.
Many of the private wells near the site are upgradient (i.e., not located in an area where the contaminated groundwater would flow) and sampling found no contaminants in these wells. Because these wells are upgradient of the site, they are not expected to be affected by site-related contamination. However, sampling during the RI found contaminants in some private wells near the site. Six contaminants (PCE, bis(2-ethylhexyl)phthalate, arsenic, manganese, thallium, and zinc) were found at concentrations above their respective CVs (Table 4). Four of the six contaminants [PCE, bis(2-ethylhexyl)phthalate, thallium, and zinc] were infrequently detected above CVs (found above CVs in less than two of the 55 samples collected and analyzed). CVs are developed for each contaminant based on the contaminant's toxicity characteristics and have a conservative margin of safety. To further evaluate exposures to these contaminants, ATSDR derived exposure doses using conservative assumptions about how often and how much water a person might drink from a well containing the maximum detected concentrations. ATSDR assumed that an adult consumed well water for 30 years and a child for 6 years. The doses derived by ATSDR were much lower than the doses reported in the toxicologic literature to result in illness or adverse health effects. PCE and bis(2-ethylhexyl)phthalate may also be released to the air during showering, however, inhalation at the levels found are not expected to result in adverse health effects.
Several private wells near the site contained arsenic at concentrations above its noncancer and cancer CVs. As mentioned above, because ATSDR's CVs are screening tools based on very conservative assumptions about exposure and toxicity, exposure to arsenic in private wells at concentrations above the CV would not necessarily result in harmful health effects. However, to further evaluate whether potential health effects may result from arsenic in private wells, ATSDR derived exposure doses using conservative assumptions about how often and how much water a person might drink from a well containing the maximum detected arsenic concentration. ATSDR assumed that an adult consumed well water for 30 years and a child for 6 years. These conservative estimates allow ATSDR to safely evaluate the likelihood, if any, that arsenic in private wells could cause harm. ATSDR's review of the toxicologic literature for arsenic suggests that the levels in the private well water are at least 10 times lower than arsenic levels shown to cause cancer or other adverse health effects in humans exposed through their drinking water. Arsenic is not released to the air during showering, therefore, there is no exposure through inhalation. Appendix F provides more information about arsenic and ATSDR's evaluation of arsenic exposures.
Manganese was detected above CVs in four of seven samples collected from one private well. To assess long-term health effects from consuming drinking water from this well, ATSDR calculated conservative exposure doses using the maximum detected concentration and conservative assumptions about exposures, as described for arsenic above. Based on these conservative scenarios, the estimated exposure doses to manganese were more than 400 times lower than doses found to cause any observable health effects in laboratory studies (10). In addition, ATSDR assumed daily exposure to the maximum detected manganese concentration; sampling indicates that manganese concentrations fluctuated and are likely much lower than the concentration assumed by ATSDR in its dose estimates. Manganese is not released to the air during showering, therefore, there is no exposure through inhalation.
Since the completion of the RI, EPA has conducted semi-annual sampling of the two private wells near the site and one private well pumping from the bedrock aquifer. No elevated contaminant concentrations have been found (3). Long-term monitoring of these wells will be included as part of the long-term monitoring program to ensure that wells are not adversely impacted by site contamination. The details of the long-term monitoring program will be finalized after operation of the pump-and-treat system is optimized (3).
Because EPA excavated and removed contaminated soil from the site, no current or future health hazards are likely associated with exposure to surface soil at the site. Because no surface soil samples were collected prior to removal of stained soil in the 1980s and early 1990s, past exposures cannot be evaluated. Therefore, ATSDR cannot evaluate potential health effects from possible soil exposures prior to these earlier cleanup activities.
From the 1940s through the 1970s, the site was used as a storage yard for surplus and salvage materials. A residential home was located and occupied on the site during this time. In the 1970s, use of the site for storage ceased and the residence was abandoned (1). The Passamaquoddy Tribe has used the Meddybemps area and Dennys River (ancestral Passamaquoddy lands) for hunting, fishing, and gathering for thousands of years. However, members of the tribe stopped using the site for subsistence plant gathering and hunting in the early 1970s because of concerns about contamination (6).
In the 1980s and 1990s, MEDEP, EPA, USACE, and DOD conducted several actions to reduce access and remove hazardous materials and physical hazards from the site. In 1985, MEDEP erected a perimeter fence that USACE, under an agreement with EPA, expanded in 1998. From the mid 1980s to the 1990s, hazardous materials such as PCB oils, waste oils, transformers, ammunition, 55-gallon drums, asbestos-containing material, and gas cylinders were removed from the site (1). Appendix C presents a time line of removal activities at the site.
In late summer 1999, EPA excavated contaminated soil and transported the soil off site for disposal. EPA determined how much soil was to be removed based on soil sampling data from RI investigations and confirmation field samples collected during the excavation activities. The confirmation field samples were collected to verify that contaminated soil was removed from the site. No additional sampling has been conducted after the soil excavation activities were completed (3).
Currently, the site is fenced to reduce access to the public, except along the shoreline of Meddybemps Lake and Dennys River. The nearest residences are on the eastern bank of Dennys River approximately 150 feet east of the site boundary. The nearest residences on the western bank of Dennys River are approximately 1/4 mile north of the site. Before soil removal actions were completed, contaminated soil may have been transported off-site as windblown dust.
Evaluation of Soil Data
From October 1996 to October 1998, surface soil (from 1 to 2 feet bgs) was extensively sampled (Appendix A, Figure 6). The data represent surface soil conditions after the removal actions during the 1980s and 1990s but before the 1999 soil remedial activities. Sampling data identified 15 contaminants at concentrations that exceeded their respective CVs (Appendix B, Table 5). Five other contaminants that do not have CVs were also detected. The most frequently detected contaminants were PCBs, antimony, arsenic, chromium, iron, lead, and mercury. PCBs were present at low concentrations throughout the northeast quadrant of the site and at one localized area near the former concrete store/office building where a large transformer was formerly stored. Dielectric fluid reportedly leaked from the transformer during storage or when the transformer was drained. VOCs were detected throughout the soils, however, two main areas with elevated contaminant concentrations (i.e., hot spots) were identified: one in the northeast portion of the site and another in the southern portion near the former concrete store/office building. The VOC hot spots contained elevated levels of benzene, toluene, ethylbenzene, and xylene (BTEX), 1,2-dichloroethylene (1,2-DCE), methylene chloride, PCE, and TCE (1). Although these areas were identified as VOC hot spots, VOC concentrations were below the CVs for surface soil.
Contamination identified in soil also affects the other pathways discussed in this public health assessment. Until the removal actions in 1999, contamination from the soil migrated into the groundwater, surface water, and sediment; was potentially distributed via windblown dust to off-site areas; volatilized into the air; and may have bioaccumulated in biota. These additional pathways are further evaluated in their respective sections.
Based on the results of soil sampling during the RI, EPA removed contaminated soil from the site to prevent future exposures. During excavation activities, EPA conducted field sampling to confirm that residual contamination was below levels determined to be protective of human health, even if the site were re-used for a residential development. EPA also conducted air monitoring and implemented dust control measures (e.g., silt fences, hay bales, concrete barriers, and water) during excavation because contaminants are most likely to migrate off-site through volatilization or windblown dust when the soil is disturbed during excavation. Air monitoring around the perimeter of the site revealed no contaminant migration during excavation (11, 12).
EPA collected surface soil samples from four off-site locations, in addition to background samples at four other locations (Appendix A, Figure 6). Three locations were between the site fence and Stone Road to the west of the site, and the fourth was across Route 191 to the south of the site (1). Two contaminants were detected above CVs: arsenic and PCBs (Appendix B, Table 6).
Public Health Implications
Current and future use of the site is not expected to result in adverse health effects. In 1999, EPA completed a removal action that involved excavating and off-site disposing of the contaminated soil. EPA removed contaminated soil to concentrations that would be unlikely to cause adverse health effects under current or possible future site uses, even if the site were re-used for a residential development. A large portion of the site will become property of the State of Maine (per a Consent Decree). The state is considering proposals to establish a park and/or conservation land for the preservation of the archaeological resources at the site. A small portion of the site will be retained by the site owner. Development in this portion of the site is not restricted by institutional controls and, although unlikely, may be used for residences (4). As such, ATSDR evaluated EPA's soil clean-up levels and found that the soil removal would reduce site contamination to below levels of health concern for all proposed land uses, including residential. Therefore, current soil conditions pose no health hazards under current or possible future site uses.
The levels of contaminants found in surface soil before the 1999 EPA excavation (but after the 1980s and 1990s removal actions) were below levels likely to cause adverse health effects to occasional site users (Table 5). Although several contaminants were found above their CVs in on- and off-site soil, the CVs are derived assuming daily exposure. From the 1980s until the 1999 soil excavation was complete, people would be expected to visit the site or areas immediately adjacent only infrequently as site trespassers. Access to the site from neighboring properties is restricted by a fence, however access along the site shoreline is unrestricted. In addition, contaminants were only detected in a portion of the samples collected, therefore, contaminants were only found above CVs in some areas of the site. It is unlikely a trespasser would be exposed to the maximum detected concentration during every site visit, especially since the maximum concentration was at least an order of magnitude higher than all the other detections. Furthermore, the majority of the detected concentrations only slightly exceeded CVs and were well below levels observed to result in adverse health effects.
Contaminant concentrations found in various hot spots before removal actions were conducted in the 1980s and early 1990s are unknown. Prior to the 1970s, a single residence was occupied by the site owner in the northeastern corner of the site. In addition, community members expressed concern over potential health problems to children who may have played at the site in the past. Based on data from the RI, the residence was not located in an area with high concentrations of surface soil contamination (1). However, because no data are available to characterize surface soil contamination at the site while the residence was occupied or how often the site may have been frequented by children, ATSDR cannot evaluate whether past exposures, either acute or chronic, may have led to adverse health effects.
Although surface soil sampling has not been conducted in residential yards near the site, these yards are unlikely to contain surface soil contaminants at levels of health concern. This conclusion was based on a review of surface soil samples collected immediately off site and an evaluation of likely contaminant transport mechanisms. Surface soil samples collected just beyond the fence line of the site contained three contaminants at levels that slightly exceeded their CVs and below levels likely to result in adverse health effects. These results indicate that off-site contaminant migration to areas just beyond the fence line has been minimal; less migration to areas further from the site would be expected.
The most likely way a contaminant from the site may have been transported to surface soil beyond the site is through windblown dust. By this mechanism, contaminated soil is picked up in gusts of wind, carried in the wind, and then deposited on the ground when the wind blows and can no longer carry the dust. Weak wind gusts carry dust only a short distance; stronger wind gusts would carry dust further. Grass and other vegetative cover, which is usually present at the site, would limit the release of dust from the site.
Windblown dust is most likely when the soil is bare or disturbed; this can occur during excavation and remediation. However, EPA monitored the air at the perimeter of the site and implemented dust control measures during excavation to reduce windblown dust. Monitoring found no contamination migrating off-site (11, 12).
Adverse health effects are not expected from past, current, or future exposures to contaminants in surface water and sediment. Reportedly, surface water from Meddybemps Lake was and is used by summer residents for drinking water. Only one contaminant was detected at a concentration slightly above its respective CV. It is unlikely, however, that exposure of summer residents to this contaminant concentration would result in adverse health effects. Contaminant concentrations found in the lake and river were below levels likely to result in adverse health effects from recreational use. While several contaminants were detected in sediments, exposures are likely to be infrequent during recreational use of these waters. Maine's cold climate restricts accessibility to sediment in the winter and contaminants were found infrequently above CVs in sediment samples. These intermittent exposures are unlikely to result in adverse health effects.
Site Drainage Characteristics
The site is located in the drainage basin for Dennys River. Although floodplain mapping has not been conducted at the site, Meddybemps Lake and Dennys River may flood the site at times of high water. Flooding may have transported site contaminants into the lake and river before soil removal actions were complete. In addition, all surface runoff from the site flows into either Meddybemps Lake or Dennys Lake. Water in Meddybemps Lake flows southerly into the upper portion of Dennys River--referred to as Mill Pond. Mill Pond continues to flow southerly into Dennys River. The outflow of Meddybemps Lake to Mill Pond is controlled by a dam at the northeast corner of the site. This dam was constructed by the Maine Atlantic Salmon Authority and is used primarily to support the Atlantic Salmon habitat in Dennys River. Eventually, Dennys River flows into Cobscook Bay and the Atlantic Ocean, approximately 27 miles downstream of the site (1).
Evaluation of Surface Water and Sediment Data
EPA collected surface water samples at 31 locations within Meddybemps Lake and Dennys River between September 1996 and June 1999 (Appendix A, Figures 7 and 8). Seven contaminants were detected above their respective CVs in surface water (Appendix B, Table 7). Antimony was detected above its CV three times, the maximum detected concentration was found in a background sample collected from a cove of Meddybemps Lake located approximately 1/4 mile southeast of the site (Appendix A, Figure 1). Antimony was the only contaminant detected above CVs in the lake. Trichloroethylene (TCE), PCE, bis(2-ethylhexyl)phthalate, arsenic, manganese, and thallium were detected above CVs with the highest concentrations located in Mill Pond at the head of Dennys River. As part of the RI findings, EPA determined that the detections of TCE and PCE in surface water were due to groundwater seepage from the northern contaminant plume. No VOCs were detected further downstream; EPA concluded that this was due to turbulence in the river facilitating evaporation of VOCs (1).
EPA collected sediment samples from 67 locations along the shoreline of Meddybemps Lake and Dennys River in September 1996 and June 1999 (Appendix A, Figures 7 and 8). Samples were collected along the shoreline of the site and within submerged areas of Dennys River. Nine contaminants were detected above their respective CVs in sediments, including PAHs, PCBs, and two metals (Appendix B, Table 8). Four additional contaminants were detected, but do not have CVs. Sampling location SD-131, had the maximum concentrations of seven of these 13 chemicals. SD-131 was located on a tributary to Dennys River southeast of the site (Appendix A, Figure 8). The highest levels of PCBs were found in sediment samples (SD-406 and SD-303) collected in Dennys River near the southern portion of the site (1).
Public Health Implications
Community members questioned whether surface water and sediments in Meddybemps Lake are contaminated because of the site and wanted to know what health effects could be expected from exposures. People may be exposed to contaminants in surface water by drinking water from Meddybemps Lake and through incidental ingestion and dermal contact during recreational activities in the lake and in Dennys River. People may also be exposed to contaminants in sediments through incidental ingestion or dermal contact with contaminated sediments during recreational activities, such as swimming, wading, or boating, in Meddybemps Lake and the Dennys River.
Past, current, and future summer residents are unlikely to suffer adverse health effects as a result of site contamination when using water from Meddybemps Lake as a drinking water supply source. Most residences near the site obtain their drinking water from private wells, however, some summer residents may use surface water from Meddybemps Lake as their drinking water supply. Only antimony, which was found in one of five samples collected from the lake, was found at a concentration slightly above its CV. Drinking water CVs are developed assuming chronic exposure--ingestion of 2 liters of water every day for 70 years. Summer residents would be exposed to antimony for 3 or 4 months a year. The CV for antimony is also based on a study of laboratory animals. In the study, the lowest dose of antimony found to cause adverse health effects in laboratory animals is thousands of times higher than the amount of antimony summer residents would ingest. In addition, antimony was only detected above its CV in one of five samples collected, therefore, people are unlikely to continuously drink water containing antimony above its CV.
Adverse health effects are not expected to result from contact with contaminated surface water during past, current, or future recreational use of Mill Pond or Dennys River. TCE, PCE, bis(2-ethylhexyl)phthalate, arsenic, manganese, and thallium were detected above drinking water CVs in surface water samples collected from Mill Pond and Dennys River (Appendix B, Table 7). Mill Pond and Dennys River are not used as drinking water supplies, but may be used for recreational purposes, such as swimming or boating. Because no CVs are available for surface water, ATSDR compared the maximum detected concentrations of contaminants found in Mill Pond and Dennys River to the CVs for drinking water. Drinking water CVs are based on a person drinking 2 liters per day over a lifetime. Recreational users would not be expected to ingest more than small amounts of water daily during swimming or boating activities. Incidental ingestion or skin contact with the contaminants during recreation would result in exposures many times lower than levels found to cause health effects in laboratory studies. Recreational use of these water bodies would be limited by the Maine climate conditions (e.g., cold temperatures and snow). Each of the contaminants found in Mill Pond and Dennys River were also only found above CVs in a small number of the samples collected, therefore, contact with levels of contaminants above CVs is unlikely to occur each time a person swims or boats in the river. Finally, the presence of PCE and TCE in the surface water is the result of on-site groundwater plumes discharging to the river. EPA is currently operating a pump-and-treat system to remove contaminants from groundwater and prevent further migration of groundwater contamination to surface water.
PAHs, PCBs, and metals were found above CVs in sediment samples collected in Meddybemps Lake and Dennys River. Two pesticides were detected at relatively low levels and did not have CVs. None of these contaminants, however, were detected at levels that might be associated with adverse health effects from recreational exposures. Because no CVs are available for sediment, ATSDR conservatively screened the maximum detected sediment concentrations against the CVs for surface soil. The surface soil CVs are developed assuming daily contact and ingestion with a contaminant in a residential yard. Recreational users, however, would only contact sediments infrequently during wading, swimming, or boating. These activities are limited through the year because of the Maine climate conditions (e.g., cold temperatures and snow). Furthermore, contaminants were found above CVs in only a few of the samples collected. In addition, CVs are developed using information about the toxicity of a chemical and applying margins of safety, making most CVs hundreds of times lower than concentrations seen to cause adverse health effects in laboratory studies.
No current or future exposures to contaminants in air are expected because all contaminant sources were removed. Therefore, no potential for adverse health effects associated with this pathway exist. Airborne contamination would be expected to be greatest during soil remedial activities, when dust particles generated from those activities could have carried contaminants off site. However, dust control measures and ambient air sampling were conducted at the site perimeter during remediation and no air contaminants were identified. Exposures to airborne contaminants may have occurred when the site was actively used as a storage yard. No data are available to characterize past releases of contaminants to the air; therefore, ATSDR cannot assess potential past exposures.
From the 1940s until the 1970s, contaminants may have been released to the air during site activities either through volatilization of stored materials or through windblown dust. To a lesser extent, contaminants may have been released to the air through volatilization from soil contamination areas or through windblown dust from the 1970s until final soil remediation in 1999. No air data are available to characterize these potential past releases. Potential sources of air contamination were removed when soil remedial activities were completed in 1999.
Two VOC hot spots in surface soil, located in the northern and southern portions of the site, were potential sources of contaminant volatilization. The VOC hot spot in the northern portion of the site encompasses approximately 4,000 square feet and mainly contained elevated levels of BTEX, 1,2-DCE, methylene chloride, PCE, and TCE. The VOC hot spot in the southern portion of the site encompassed approximately 1,500 square feet near the former hydroelectric power unit. This hot spot contains elevated levels of BTEX, methylene chloride, PCE, and TCE (1). Although these areas were identified as VOC hot spots, VOC concentrations were below the CVs for surface soil. The VOC hot spots were removed as part of the soil remediation completed in 1999.
Surface soil contaminants, as described in the surface soil discussion section of this PHA, were available for transport in windblown dust. These contaminants were removed from surface soil during the 1999 surface soil remediation activities.
Evaluation of Air Data
In 1997, EPA collected ambient air samples to assess whether VOCs in the two hot spot areas may be migrating off site. Three rounds of sampling were conducted in June, October, and November. Sample points were located within the hot spot areas, around the perimeter of the hot spots, and near the site boundary. Samples were collected continuously for 2- or 8-hour periods at a height of 1 to 2 feet above the ground surface. Only benzene (39 micrograms per cubic meter [µg/m3]) was found above its CV in one sample collected at the perimeter of the northern VOC hot spot. Benzene was not found in the other ambient air samples (13).
During soil remediation efforts conducted in the summer of 1999, EPA implemented dust control measures to minimize off-site contaminant migration. EPA also collected ambient air samples to monitor contaminant releases and migration. Monitoring around the perimeter of the site did not identify contaminants in air (11, 12).
Public Health Implications
Community members expressed concern about potential health effects from breathing airborne contaminants from the site, particularly in the past. Available sampling data suggest no VOCs and other airborne contaminants migrated off site during the 1999 site remediation activities (11, 12). During remediation, the soil contamination, including the VOC hot spots, were removed. Therefore, sources of air contamination were removed and no current or future health hazards are present. No additional monitoring is planned or necessary.
Past exposures to airborne contaminants may have occurred when the site was used as a storage yard and before site remediation began in the 1980s and continued in the 1990s. Contaminants may have volatilized or evaporated from open containers, may have been released from gas cylinders, or may have volatilized from surface soil. No data are available to characterize potential releases before 1997; the data from 1997 only characterize airborne contaminants at that time. The 1997 sampling event found benzene above its CV in an ambient air sample collected near the VOC hot spot and close to the ground. The benzene concentration found in off-site air would be much lower than found on site based on dispersion during wind transport. Benzene was also found in only one of the samples collected over three sampling rounds. Because airborne contaminants are transitory and continuously changing, the available 1997 data are not useable to characterize past site conditions. ATSDR, therefore, cannot assess potential past exposures.
Exposures to contaminants in biota (fish, plants, and animals) cannot be fully characterized from the available data; therefore, ATSDR is unable to evaluate past (potential) exposures and health effects from exposures to contaminants in biota. To be able to evaluate current and future potential exposures to contaminants in fish and plants, ATSDR recommends additional fish and shellfish sampling to better characterize possible contamination in these food sources. EPA and members of the Passamaquoddy Tribe agreed to conduct a site visit to identify plants used for consumption or medicinal purposes. ATSDR will evaluate additional sampling and surveying data when they become available to evaluate current and potential future exposures. Although no data are available to characterize contaminant levels in animals, ATSDR does not expect any current or future health-related problems. Nobody currently hunts at the site and the remedial activities cleaned the soil to levels that would not be expected to result in animals collecting contaminants in their bodies at levels that would be of health concern.
The site is located along the shoreline of Meddybemps Lake and Dennys River, which are both used for recreational purposes, including fishing. In addition, members of the Passamaquoddy Tribe formerly used the site land for subsistence hunting (e.g., moose, deer, and muskrat) and fishing, as well as gathering plants for medicinal and tribal practices, but reportedly stopped in the late 1970s because of concerns about pollution (6). The Passamaquoddy Tribe has expressed interest in resuming their use of the site for more extensive fishing, hunting, and plant gathering.
Evaluation of Biota Data
Between September 22 and 27, 1997, fish were caught from six locations near the site and one reference location. The fish were analyzed as fillets--which are the part of the fish most often eaten--and as whole fish (Appendix B, Tables 9 and 10). The sample locations included Staples Cove and Fowler Point north of the site, Meddybemps Lake and Dennys River near the site, and Dennys River and Dead Stream downstream of the site. At each sample location, 10 fish (five each of either small mouth bass, pumpkinseed, white sucker, or brook trout) were collected and analyzed (1). Pesticides, PCBs, and metals were found above CVs in the whole body fish samples and fish fillets samples. Lead was also detected, but has no CV.
During the fish sampling, mussels were also collected at the sample locations, except at Dead Stream, and one reference location (Appendix B, Table 11). Five mussels (either Eastern elliptio or alewife floater) were collected at each sample location (1). PCBs and metals were found in mussel samples at concentrations above CVs. Because fish and mussel samples were collected over a 5-day period, these data only provide a picture of contamination at that time.
No plant or land animal data have been collected at the site. As discussed previously in this public health assessment, SVOCs, pesticides, PCBs, and metals were found in surface soil above CVs. VOCs, SVOCs, pesticides, PCBs, and metals were found in surface water and/or sediment samples above CVs. Contaminants present in surface soil, surface water, and sediment may have been available to bioaccumulate in any plants growing in contaminated areas or animals that frequented contaminated areas.
Public Health Implications
Community members expressed concern that fish in Meddybemps Lake and Dennys River are contaminated and inedible as a result of contaminant releases from the site. Members of the Passamaquoddy Tribe expressed specific concerns about the potential for unique health problems from use of culturally significant plants and animals for consumption, medicinal practices, and other cultural practices. Tribe members specifically mentioned deer, moose, muskrat, and Atlantic salmon as animals important to their culture.
Animals, both terrestrial (land) and aquatic (water), may bioaccumulate contaminants by drinking water that contains contaminants, eating plants that have stored contaminants, or eating contaminated soil or sediment. People that hunt or fish in the area may ingest animal tissue that contains bioaccumulated contaminants. Plants may bioaccumulate contaminants from soil or sediment in their stems, roots, leaves, or fruit. Therefore, people that eat plants growing in contaminated soil may ingest those bioaccumulated contaminants. Without sampling data, however, the presence or absence of contaminants bioaccumulated in animal or plant tissue cannot be confirmed.
Consumption of Fish and Shellfish
One-time sampling data from 1997 identified pesticides, PCBs, and metals, including mercury, in fish and/or shellfish tissue samples. Based on a review of the tissue data, possible exposure frequency, and toxicologic data, people who caught and consumed fish or mussels from Medddybemps Lake during that time are not expected to experience adverse health effects. However, ATSDR cannot assess potential current and future health effects based on data from this single sampling event. ATSDR recommends that EPA collect additional fish and mussel samples from Meddybemps Lake and Dennys River. Additional sampling should provide data that will help document the nature and extent of contamination in edible fish and mussel species, seasonal variations, and variations in size and age, and address the Passamaquoddy tribe's concerns about fish and salmon. At a minimum, both fillet and whole body samples should be analyzed for PCBs and mercury.
In 1994, with updates in 1997 and 2000, the Maine Bureau of Health issued a state-wide fish consumption advisory based on mercury concentrations found in freshwater fish throughout the state. The mercury advisory states that pregnant and nursing women and children under 8 years old should not consume fish from freshwater lakes and rivers throughout Maine. Children over 8 years old and adults should limit their intake to only one or two fish meals per month. This advisory is based on studies that have shown that mercury can harm a brain starting to form or develop. The mercury advisory applies to all freshwater fish, regardless of size, found in Maine (14). This action is not a direct response to contamination from the site, but is a result of mercury found throughout the state.
This same advisory also specifically identifies several water bodies, including Dennys River from Meddybemps Lake to Dead Stream, where fish consumption should be limited based on PCB concentrations found in freshwater fish. The PCB advisory states that adults and children should limit their intake to only one or two fish meals per month. This advisory is based on studies that have shown that PCBs can cause cancer and other health effects. The PCB advisory applies to all freshwater fish, regardless of size, found in Dennys River from Meddybemps Lake to Dead Stream. Neither of the advisories provide any preparation or cooking guidelines for people consuming fish (14). ATSDR encourages people to continue following the fish consumption advisories for mercury and PCBs to avoid possible health effects.
No data are available to characterize contaminants in fish or shellfish prior to the early 1970s, when Meddybemps Lake and Dennys River may have been used for subsistence fishing. Therefore, ATSDR cannot evaluate potential past health effects associated with subsistence exposures.
Consumption of Plants and Land Animals
No data are available to characterize contaminants that may be present in plants and land animals at the site. Therefore, ATSDR cannot evaluate current or future potential health effects associated with various uses of plants. Although no data are available, ATSDR evaluated potential current and future health effects from hunting by examining the likelihood of animals collecting contaminants in their bodies at levels that would be of health concern. Members of the Passamaquoddy Tribe ceased using the site in the 1970s, however, they would like to resume fishing, hunting, and plant gathering at the site (6).
To assess possible current and future exposures to contaminants in plants, EPA and members of the Passamaquoddy Tribe agreed to survey the site to identify plants used for tribal purposes. ATSDR will examine survey results and evaluate possible health hazards associated with the use of these plants.
To assess possible current and future exposures to contaminants in animals (e.g., deer), ATSDR considered the likelihood of animals accumulating harmful levels of contaminants in their bodies. In order to accumulate contaminants, an animal must be exposed to site contaminants. MEDEP, EPA, and DOD have completed a number of remedial actions at the site, most recently in the fall of 1999, and groundwater remediation continues at the site (1). These activities reduced site contaminants to below levels that would collect in animals at levels of concern. However, a number of animals may still be living that may have been exposed to site contaminants before remediation started. Animals are transient and move from place to place. Therefore any exposure to contaminants would have been limited to only time spent within site boundaries. For these reasons, ATSDR does not expect that animals, still living, would have been exposed to site contaminants in sufficient amounts to accumulate at levels that would result in adverse health effects to a person consuming hunted animals.
In order to evaluate this conclusion, ATSDR also considered whether or not sampling animal tissue would provide additional information for assessing exposures to people consuming hunted animals. Because animals are transient, tissue samples would represent the animal's exposures at the site, as well as any other place where exposures may have occurred. Exposures at the site could not be distinguished from exposures at other places. In addition, animals move independently of each other, so tissue samples from one animal may not represent contaminant levels in the tissue of another animal or herd of animals. ATSDR believes that no tissue sampling is necessary because data would be of limited use and remedial actions to prevent accumulation of contaminants in animals have been completed.
No data are available to characterize contaminants in plants or animals prior to the early 1970s, when the site may have been used for subsistence hunting or plant gathering for medicinal or other cultural practices. Therefore, ATSDR cannot evaluate potential past health effects from these practices.
Through several remedial and removal actions, MEDEP, EPA, and DOD removed hazardous waste materials and debris from the site. There should not be any remaining unexploded ordnance on the site. Therefore, no physical hazards remain at the site, except a dilapidated hydroelectric power unit. This hydroelectric unit will not be transferred to the State of Maine and remains under private ownership. The remains of this hydroelectric power unit straddle Dennys River and are accessible from the river or from the east bank of the river. Access to the hydroelectric power unit from the west bank of Dennys River is restricted by a fence around the site (1). The unit is in a state of disrepair and may pose a risk of injury or harm to trespassers. There are currently no plans to either repair or demolish this structure (3).
Government agencies often collect health information from populations in different geographic areas; many state health departments have developed registries of illnesses and disease; some county and local health departments periodically collect health information; and community members and groups may also collect health information for particular areas of interest. These data can be evaluated to identify trends in populations and any unusual increases in disease in specific areas. ATSDR did not identify any relevant health outcome data for the site vicinity. The Maine Department of Health would maintain health outcome data or health study results for the site, however, the only records available are birth and death certificate records or cancer registries, which are collected for people throughout the state.
Children are at greater risk of health effects from exposures to hazardous substances than adults because they: 1) play outside more often than adults (increasing the likelihood of contact with chemicals in the environment); 2) are shorter than adults and more likely to be exposed to soil, dust, and heavy vapors close to the ground; 3) are smaller than adults and their exposures would result in higher doses of chemical per body weight; and 4) have developing body systems which can sustain damage if toxic exposures occur during certain growth stages. Therefore, ATSDR evaluated how children might be affected by the types and quantities of chemicals detected in site media (groundwater, surface soil, surface water and sediment, air, and biota), seeking to determine if detected contaminant levels might be associated with any reproductive or developmental effects.
Children have limited access to the site and to areas surrounding the site because of site access restrictions (e.g., fences). When evaluating potential exposures presented in the Discussion section of this public health assessment (e.g. exposure to contaminants in drinking water or fish), ATSDR used the most conservative CVs for children while evaluating the data. Available data on groundwater, surface soil, surface water, sediment, and air indicate no additional risk to children from these media. Insufficient data are available to assess potential health hazards to children or adults from use of site biota. Parents, however, should adhere to the Maine Bureau of Health state-wide fish consumption advisory for mercury and the Dennys River fish consumption advisory for PCBs. Based on potential effects from mercury, the state recommends that pregnant or nursing women and children under 8 years old should not consume fish from Meddybemps Lake or Dennys River. Children over 8 years old and adults should limit their fish intake to only one to two fish meals per month. The advisory applies to all freshwater fish, regardless of size, found in Maine. Based on potential effects from PCBs, the state recommends that neither children nor adults consume more than one to two fish meals per month for fish caught in Dennys River between Meddybemps Lake and Dead Stream. These advisories do not provide any preparation or cooking guidelines for people consuming fish (14).
ATSDR classifies the site as an indeterminate public health hazard. (The definition of ATSDR's public health conclusion classifications are provided in Appendix E.) ATSDR classifies current and future exposures at the site as posing an indeterminate public health hazard. This classification is based on the fact that there were limited fish data and no plant data to address community health concerns and to make a public health call related to these potential exposure pathways. The only data available to assess exposures through use of site biota are the result of a single fish and mussels tissue sampling event conducted over one week in fall 1997. No data are available to characterize potential contamination in plants. The Passamaquoddy Tribe has expressed interest in resuming their use of the site for more extensive fishing, hunting, and plant gathering.
Based on a review of available environmental data collected during extensive site investigations, ATSDR determined that other potential exposure pathways (groundwater, surface soil, surface water, sediment, and air) pose no current or future public health hazards. Furthermore, EPA has conducted remedial actions (e.g., groundwater treatment and soil removals) to reduce or eliminate current and future exposures to contaminants in these media. ATSDR evaluated EPA's soil clean-up levels to confirm that they were protective of public health. No data were available to characterize contaminant levels in animals, therefore, ATSDR assessed potential exposures to contaminants collecting in animals by evaluating the likelihood of animals being exposed to site contaminants and the extent to which people are hunting animals at the site. ATSDR found no current health effects because the site is currently not used for hunting. No future health effects are expected because site remediation has reduced the concentrations of site contaminants to concentrations that would not result in adverse health effects from exposures; an animal exposed to the residual levels of contaminants would not be expected to collect contaminants in its body at a level of health concern for humans consuming meat from animals hunted at the site.
ATSDR characterized past exposures at the site as an indeterminate public health hazard. No data are available to characterize past exposures (i.e., prior to remedial activities in the 1980s and 1990s) to contaminants in surface soil, air, and biota (plants and animals).
- Additional fish and mussel samples should be collected to assess potential health hazards from current and future fishing in Meddybemps Lake and Dennys River. Specifically, fillet and whole body fish samples should be analyzed for PCBs and mercury. Additional sampling should provide data that represent the nature and extent of contamination in edible fish and mussel species, seasonal variations, and variations in size and age. Since the Passamaquoddy tribe specifically named the Atlantic salmon as being important to the tribe, ATSDR recommends these species be sampled in addition to the other fish samples to address community health concerns.
- ATSDR supports the agreement between EPA and members of the Passamaquoddy Tribe to survey the site to identify plants used for tribal purposes. ATSDR will review the available data and provide information to the Passamaquoddy Tribe and the community regarding the data evaluation as they become available.
- The site owner should consider demolishing or implementing access restrictions to prevent trespassing at the dilapidated hydroelectric power unit straddling Dennys River in the southern portion of the site and to eliminate this physical hazard.
This Public Health Action Plan (PHAP) was developed for actions needed at the site. The purpose of the PHAP is to ensure that this public health assessment identifies public health hazards and to provide a plan of action designed to mitigate and prevent adverse human health effects that may result from exposure to hazardous substances in the environment. The public health actions that are completed, being implemented, or planned are as follows:
- Between the late 1980s and early 1990s, MEDEP, EPA, and DOD removed hazardous materials (e.g., chemicals stored in drums and stained soil) and physical hazards (e.g., debris and gas cylinders) that posed an immediate threat to human health.
- In 1999, EPA installed a groundwater pump-and-treat system to cleanup groundwater contamination at the site and prevent off-site migration. The system began operating in January 2000.
- In late summer 1999, EPA excavated contaminated soil and sampled the soil to ensure levels met standards developed to protect public health even if the site were redeveloped for residential use. The effort was completed in September 1999 and contaminated soil was transported for off-site disposal.
- In 1994, with updates in 1997 and 2000, the Maine Bureau of Health posted a state-wide fish consumption advisory for freshwater fish caught in all Maine water bodies because of a state-wide concern about mercury in water bodies throughout Maine. This advisory recommends that pregnant or nursing women and children under the age of 8 abstain from eating freshwater fish caught in Maine. Children over the age of 8 and adults should limit their fish intake to one or two meals per month. The advisory applies to all freshwater fish, regardless of size, found in Maine. This advisory also recommends limited consumption of fish from Dennys River based on PCB contamination concerns. This advisory applies to all fish caught between Meddybemps Lake and Dead Stream. Adults and children are advised to limit their fish consumption to one to two fish meals per month. The advisory does not provide any preparation or cooking guidelines for people consuming fish.
- In September 2000, EPA signed a ROD outlining remedial actions required at the site. Remedial actions include operation of a ground water pump-and-treat system to remove contaminants from groundwater and to prevent contaminant migration. The ROD also requires long-term monitoring to ensure that the pump-and-treat system is properly functioning to prevent migration.
- EPA will continue to operate the groundwater pump-and-treat system at the site to remediate groundwater contamination. EPA is also investigating in-situ oxidation as a potential remedial action to supplement the pump-and-treat system.
- EPA is coordinating with the State of Maine--the future site owner--to establish institutional controls, such as deed restrictions, that will prevent future uses of groundwater through legal restrictions on allowable site uses.
- To confirm that remediation activities at the site are successful, EPA is preparing a long-term monitoring program that will include monitoring groundwater, surface water, and sediment. In addition, the two private wells closest to the site will be included in the long-term monitoring program. The long-term monitoring plan will be prepared after the operation of the pump-and-treat system addressing groundwater contamination at the site is optimized.
Environmental Health Scientist
Superfund Site Assessment Branch
Division of Health Assessment and Consultation
W. Allen Robison, PhD.
Superfund Site Assessment Branch
Division of Health Assessment and Consultation
Superfund Site Assessment Branch
Division of Health Assessment and Consultation
ATSDR Regional Representative
Office of Regional Operations
ATSDR Regional Representative
Office of Regional Operations
- TetraTech NUS, Inc. 1999. Final Remedial Investigation Report, Eastern Surplus Company Site, Meddybemps, Maine. August 1999.
- U.S. Environmental Protection Agency. 1999. Fact Sheet: EPA proposes long-term cleanup plan for the Eastern Surplus Company Superfund Site. August 1999.
- Chu, L. 2000. Personal communication with Liyang Chu, TetraTech NUS, Inc. July 20, September 14, November 8, 2000, and February 21, 2001.
- U.S. Environmental Protection Agency. 2000. Record of Decision for Eastern Surplus Company Superfund Site. September 2000.
- U.S. Bureau of Census. 2000. 1990 Census of Population and Housing data. Downloaded August 21, 2000.
- Doyle, R. and R. Stevens. 1999. Correspondence from Richard Doyle, Tribal Governor, Pleasant Point and Richard Stevens, Tribal Governor, Indian Township to Ed Hathaway, EPA. RE: Comments to Proposed Site Cleanup Plan, Eastern Surplus Co. Superfund Site by the Passamaquoddy Tribe. December 17, 1999.
- Tufts University. no date. Comments on Risk Assessment, Eastern Surplus Supply Site, Meddybemps, Maine. Tufts University TOSC Project.
- Agency for Toxic Substances and Disease Registry. 1997. Revised Site Review and Update, Eastern Surplus Company, Meddybemps, Washington County, Maine. November 10, 1997.
- Simon, S. 2000. Personal communication with Susanne Simon, ATSDR. September 18, 2000.
- Agency for Toxic Substances and Disease Registry. 1997. Toxicological Profile for Manganese (Update). U.S. Department of Health and Human Services. September 1997.
- U.S. Environmental Protection Agency. 1999. Fact Sheet: EPA Cleanup Update, Eastern Surplus Company Superfund Site. July 1999.
- U.S. Environmental Protection Agency. 1999. Fact Sheet: Site Activity Update: Excavation Work Continues, Eastern Surplus Company Superfund Site. August 1999.
- U.S. Environmental Protection Agency. 1997. Ambient Air and Soil Gas Sampling Report, Eastern Surplus Company, Meddybemps, Maine. June 1997.
- Maine Bureau of Health. 2000. Warning about Eating Freshwater Fish. Environmental Toxicology Program. Revised August 29, 2000. Available at: http://www.state.me.us/dhs/etp/fca.htm
- U.S. Environmental Protection Agency. 1997. Exposure Factors Handbook. National Center for Environmental Assessment. EPA/600/P-95/00Fa. August 1997.
- Agency for Toxic Substances and Disease Registry. 1998. Toxicological Profile for Arsenic (Update). U.S. Department of Health and Human Services. August 1998.
- National Research Council. 1999. Arsenic in Drinking Water. National Academy Press.
- U.S. Environmental Protection Agency. 2000. Site Activity Update, Eastern Surplus Company Superfund Site, Record of Decision Signed. Community Update #19. December 2000.