PUBLIC HEALTH ASSESSMENT
AYER, MIDDLESEX COUNTY, MASSACHUSETTS
The Agency for Toxic Substances and Disease Registry (ATSDR) has prepared this public health assessment to evaluate potential exposure pathways for contaminants from the Fort Devens site to cause harm to people living near or accessing the site. From a review of the available environmental data and exposure information, ATSDR finds that the Fort Devens site poses no apparent public health hazard.
Fort Devens is located 35 miles northwest of Boston, Massachusetts. The site covers approximately 9,311 acres in the towns of Ayer, Harvard, Lancaster, and Shirley. Initially established as a temporary training camp, Fort Devens eventually processed military equipment. During normal operations, some processing chemicals were released to the surrounding soil and groundwater, and other environmental media. In 1989, the U.S. Environmental Protection Agency (EPA) placed the site on the National Priorities List because groundwater was contaminated by volatile organic compounds (used to clean equipment) and/or metals. Most of the contamination reportedly is contained within the Fort Devens property, although some contamination has migrated via groundwater to an adjacent property.
In evaluating potential public health hazards at Fort Devens, ATSDR reviewed available information from Fort Devens, the Ayer Department of Public Works, the Massachusetts Department of Environmental Protection, the Massachusetts Department of Public Health, the Massachusetts Department of Environmental Management, Massachusetts Development Finance Agency (MassDevelopment, and formerly known as Devens Commerce Center), Nashoba Associated Board of Health, and EPA. ATSDR also held public availability sessions in Ayer, Harvard, Lancaster, and Shirley to hear health concerns of residents living near Fort Devens, and prepared health consultations to respond to some of their concerns.
From a preliminary review of the data and community discussions, ATSDR identified contaminated groundwater that might feed into public or private drinking water supplies as the principal exposure pathway of concern. After reviewing available data in greater detail, however, ATSDR determined that site-related contaminants pose no public health hazard to people who currently use, or people who have used, area drinking water supplies. The Army continues to take measures to reduce potential future exposures to groundwater by identifying and intercepting contaminants before they can reach area drinking water supplies.
ATSDR also evaluated potential exposures from contacting Grove Pond and Plow Shop Pond surface water and sediment, breathing indoor air at the former Devens Elementary School, and eating pond fish. In evaluating these pathways, ATSDR considered whether people might have been (past), are (current), or could be (future) exposed to contaminants from Fort Devens at levels known to cause public health hazards. Following its review, ATSDR has drawn these conclusions:
- No harmful exposures have occurred in the past, nor are likely to occur for people who wade, boat, or catch and release fish, at Grove Pond and Plow Shop Pond. Advisories currently recommend against swimming at either pond.
- Air inside the former Devens Elementary School poses no current or future public health hazards from contaminants associated with historic fuel oil spills. Although limited data were collected around the time of the release, information gathered to date suggest the air inside the school was probably not adversely impacted in the past.
- People most likely were not exposed to harmful levels of contaminants when they ate fish in the past from Grove Pond, Plow Shop Pond, or Mirror Lake. Advisories currently recommend that people limit or refrain from consumption of fish caught from these ponds. As a precautionary measure, people can best protect themselves by continuing to follow the recommendations in the advisory posted at each of these water bodies.
Fort Devens (also known as the Reserve Forces Training Area [Devens]) is a military base located approximately 35 miles northwest of Boston, Massachusetts. The site covers approximately 9,300 acres in the towns of Ayer, Harvard, Lancaster, and Shirley (BRAC, 1996). As Figure 1 indicates, Fort Devens is divided into three functionally distinct parts: the Main Post, the North Post, and the South Post (Fort Devens, 1995a). The three posts are described below:
Main Post. The Main Post, situated on 3,528 acres, was the center for residential, industrial, educational, and recreational activities at Fort Devens. Most of the Main Post is located in the town of Harvard.
North Post. Located north of West Main Street in the towns of Ayer and Shirley, the 900-acre North Post contains the Moore Army Air Field, the installation's water treatment plant, and training areas. The wastewater treatment plant does not currently meet Massachusetts standards. The post Reuse Plan calls for its replacement with a state-of-the art water treatment plant.
South Post. Separated from the Main Post by Route 2, the 4,883-acre South Post has been and is still used for firing practices and training. The area, also known as the Tactical Training Area or the South Post Impact Area, is entirely within the boundaries of the town of Lancaster.
Fort Devens was established in 1917 as Camp Devens, a temporary training camp for military personnel. By 1931, the camp had become a permanent installation, known as Fort Devens, for the training and induction of military personnel and the processing of military equipment. More recently, Fort Devens has "demobilized" and "out processed" equipment assigned to Army units in New England (BRAC, 1996).
In support of its mission, the Army conducted operations (e.g., storage and distribution of fuel oil, maintenance of vehicles and air crafts, photographic processing, and landfilling) that used a variety of chemicals. As a result of these past operations and waste disposal practices, hazardous materials have been released to the environment. Some of these chemicals, including volatile organic compounds (VOCs), explosive compounds, fuels, and, perhaps, inorganic compounds (e.g., arsenic) might have been released to the soil and into the underlying groundwater (BRAC, 1996). Most of the contamination reportedly is contained on the Fort Devens property, though some contamination has migrated via groundwater to adjacent property. Today, hazardous material and wastes generated at the property are disposed off or recycled at off-site waste disposal facilities.
In 1989, the U.S. Environmental Protection Agency (EPA) placed Fort Devens on the National Priorities List (NPL) of sites identified for possible long-term remedial response. The post was placed on the list as a result of VOC contamination in groundwater at Shepley's Hill Landfill, metal contamination in groundwater at Cold Spring Brook Landfill (area of contamination [AOC] 40), and the proximity of these locations to drinking water wells (Grove Pond Wells and Patton Well) (Fort Devens, 1995b).
The Army has conducted numerous and extensive investigations of environmental contamination associated with past operations and waste handling practices at Fort Devens through its installation restoration program (IRP). Over the years, more than 300 sites have been identified for environmental investigation, including landfills, industrial areas, gas stations, post spill sites, waste storage areas, and underground and above ground storage tanks. Most of the sites have been investigated under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), also known as Superfund (Horne Engineering Services, Inc., 1996), many of which have been designated as requiring no further action, while other sites are in varying stages of cleanup with Massachusetts Department of Environmental Protection (MADEP) and EPA oversight. Table 1 describes the use, chemical contamination, and current status of many of the study areas and AOCs at Fort Devens.
The Federal Base Realignment and Closure (BRAC) Commission has since recommended closing Fort Devens, and retaining a reserve enclave, which includes all of the South Post Impact Area and significant portions of the Main and North Post. The goal of the BRAC is to quickly transfer excess military property (about 50 percent of the total acreage) to other parties for economic reuse and development. To guide remedial activities at Fort Devens, the Army has grouped study areas and AOCs that share similar contaminated media or geographic proximity and assigned them to one of six operable units (Fort Devens, 1998).
Today, the Main Post and North Post are not actively used for military support, but the South Post is and will continue to be used by the Army for military training. In 1996, large portions of the Main Post and North Post were transferred to the local redevelopment authority, the Massachusetts Government Land Bank, for the development of the Devens Regional Enterprise Zone (referred to as "Devens"). A Reuse Plan outlines many of the proposed uses for the enterprise zone. Once transferred or leased, the management of the physical property and associated environmental issues will be the responsibility of the Massachusetts Development Finance Agency (MassDevelopment, also previously known as Devens Commerce Center). Any ongoing major environmental response actions at Fort Devens will continue to be managed by the Army (BRAC, 1996; MADEP, 1999a). With state legislative approval, the area will eventually be transferred to the local community for economic development and reuse (MADEP, 1998a; Vanasse Hangen Brustlin, Inc., 1994). For ease of presentation, this PHA will refer to the site only as "Fort Devens" and will no longer refer to the site as "Devens."
As part of the public health assessment process, the Agency for Toxic Substances and Disease Registry (ATSDR) conducted an initial scoping visit and met with representatives from the Army, Fort Devens, EPA, MADEP, and Massachusetts Department of Public Health (MDPH) in March 1991. ATSDR gathered information on potential pathways of human exposure to contaminants and held session(s) with the public to gather information about community health concerns. From these meetings and a review of the data then available, ATSDR determined that no immediate threats to public health existed, but that several potential exposure pathways and community health concerns required further evaluation.
ATSDR has revisited the Fort Devens site on several occasions, to confirm that no situations requiring immediate attention existed and to further evaluate community health concerns. ATSDR has also attended Restoration Advisory Board (RAB) meetings throughout the years in order to remain current with environmental and health issues. At the request of MADEP, ATSDR evaluated potential health hazards associated with explosive compounds in groundwater underlying the South Post. In a December 1994 health consultation, ATSDR presented its conclusion that explosive compounds were not likely to move from the source areas to drinking water supplies.
As part of its ongoing involvement at Fort Devens, ATSDR conducted another site visit and met with representatives from the Army, MADEP, and EPA on March 23, 1998. Also, ATSDR met with representatives of the U.S. Department of Justice, Federal Bureau of Prisons, Nashoba Associated Board of Health, League of Women Voters, Ayer Department of Public Works, U.S. Fish and Wildlife Service, Nashua River Watershed Association, Ayer Committee for Community Wellness, Devens Reuse Task Force, and MassDevelopment. ATSDR attended a RAB meeting, where ATSDR staff listened to community health concerns and presented an overview of the public health assessment process (ATSDR, 1998). ATSDR has continued to attend RAB meetings throughout the year where ATSDR presented information as well as gathered additional community concerns. In March 1998, ATSDR also held public availability sessions in Ayer, Harvard, Lancaster, Shirley, and at Fort Devens to provide an additional opportunity for the public to express any site-related health concerns. More than 50 people attended these sessions. ATSDR addresses the public's health concerns in the "Evaluation of Potential Exposure Pathways" and "Community Health Concern" sections of this public health assessment.
From the public availability meetings, ATSDR learned that community members were particularly concerned about the possibility of health effects from drinking water drawn from the Ayer Grove Pond wells and from recreational uses of Grove Pond and Plow Shop Pond. In response, ATSDR developed focused health consultations and fact sheets on the health consequences of drinking Ayer Grove Pond well water (July 1998) and recreational uses of Grove Pond and Plow shop Pond (December 1998). This PHA summarizes the findings of these health consultations, as well as assesses other potential pathways of exposures (e.g., indoor air at the Devens Elementary School), and responds to specific health concerns expressed by community members.
ATSDR examines demographic information, or population information, to identify the presence of sensitive populations, such as young children and the elderly, in the vicinity of a site. Demographics also provide details on residential history in a particular area--information that helps ATSDR assess time frames of potential human exposure to contaminants. Demographic information for the residential areas surrounding Fort Devens is presented in this section.
Fort Devens has been a major employer of military and civilian personnel for the area. According to the 1990 census data, Fort Devens supported more than 2,200 civilian and 6,200 military personnel. About 80% of the military personnel (about 4,900 persons) and family members (4,280 persons) stationed at Fort Devens lived on post. Many military retirees also used services provided by the post. Since closure procedures began, the Fort Devens workforce has decreased to a daytime population of about 900 civilian and 250 military personnel (Ecology and Environment, 1994; Fort Devens, 1999a). The daytime population is expected to increase as businesses move into the newly created enterprise zone at Fort Devens (Fort Devens 1999a).
A number of small towns are located around Fort Devens, the nearest of which are Ayer, Harvard, Lancaster, and Shirley. The towns of Ayer (population of 6,029 persons) and Shirley (population of 5,473 persons) abut the Main Post to the north and west, respectively. Portions of Lancaster (population of 6,610 persons) lie adjacent to the South Post and to the east of the site is the town of Harvard (population of 6,816 persons) (Vanasse Hangen Brustlin, Inc., 1994). Figure 2 shows demographic information for the population within a 1-mile radius of Fort Devens boundaries. As the figure indicates, approximately 20,000 residents of the surrounding communities live within a 1-mile buffer of the site boundaries, including approximately 2,600 children ages 6 and under and 1,000 adults ages 65 and older (ATSDR, 1999).
ATSDR also reviewed land use at or near the Fort Devens site to identify valuable information on the types and frequency of activities of the surrounding population and the possibility of exposure through these activities. The predominant land use in the four towns surrounding the site is residential, while commercial and industrial uses are concentrated along Route 2A. Still, large portions of undeveloped, wooded, and open pasture land exist in the four town region. One of the larger undeveloped areas is the Oxbow National Wildlife Refuge, which is located along the east-central portion of Fort Devens. Some nearby land is also used for agriculture, particularly in the town of Harvard where several orchards exist (Vanasse Hangen Brustlin, Inc., 1994).
Groundwater at Fort Devens is found largely in the permeable glacial-deltaic outwash deposits of sand, gravel, and boulders. Small amounts of groundwater can also be obtained from the fractured bedrock aquifer. The top of the saturated zone, or water table, in the area of Fort Devens is encountered about 0 to 90 feet below ground surface (Vanasse Hangen Brustlin, Inc., 1994). Groundwater flow direction varies locally, but is generally toward the Nashua River (Ecology and Environment, 1994).
Groundwater, which meets MADEP's designation as a Class I potable water source, serves as a major source of drinking water for the region (Vanasse Hangen Brustlin, Inc., 1994). Each of the four towns and Fort Devens provides groundwater-supplied public drinking water to its residents. Table 2 describes the location, history, and use of area public drinking water wells. Some water is drawn from the medium- or high-yield aquifers lying beneath portions (about 30%) of the Fort Devens property.
Some area residents rely on private wells in lieu of public water. While no complete list of active private wells in the area currently exists, through a review of files at the Massachusetts Department of Environmental Management and information obtained from the Nashoba Boards of Health, ATSDR estimates that approximately 700 private wells have been installed in the four town area since the 1960s. Of these wells, roughly 100 to 300 private wells are located within a 1- mile buffer of the Fort Devens site. A few wells serve industrial and agricultural purposes, but most wells are registered for domestic uses (MDEM, 1999; Nashoba Associated Board of Health, 1999). Because of the limitations of these data and the absence of recent well information, we do not know with certainty, however, whether the private wells are still used, or even if they have ever been used.
Fort Devens is located within the Nashua River Basin and more than 8 miles of rivers and streams flow through its property (Vanasse Hangen Brustlin, Inc., 1994). About 100 acres of ponds and lakes are used for outdoor recreation, including Robbins Pond, Mirror Lake, and Little Mirror Lake (Vanasse Hangen Brustlin, Inc., 1994). Two other ponds, Grove Pond and Plow Shop Pond, are situated along the northern boundary of the Fort Devens property. To reduce potential exposure to contaminants that might be present fish and/or sediment, Mirror Lake is posted with a fish consumption advisory and Grove Pond and Plow Shop Pond are posted with a catch and release fishing only and no swimming advisory.
In preparing this public health assessment, ATSDR relied on the information provided in the referenced documents. Documents prepared for the IRP program meet specific standards for adequate quality assurance and control measures for chain-of-custody procedures, laboratory procedures, and data reporting. The validity of the analyses and conclusions drawn in this document are dependent upon the availability and reliability of the referenced information. The environmental data presented in the public health assessment are from the environmental investigations for Fort Devens; water quality data provided by the Ayer Department of Public Works; and additional data provided by the EPA, MADEP, and MDPH. The limitations of these data have been identified in the associated reports.
In this section, ATSDR evaluates whether community members have been (past), are (current) or could be (future) exposed to harmful levels of chemicals. Figure 3 describes the conservative exposure evaluation process used by ATSDR. As the figure indicates, ATSDR considers how people might come into contact with, or be exposed to, contaminated media. Specifically, ATSDR determines whether an exposure could occur through ingestion, dermal (skin) contact with contaminated media, or inhalation of vapors, and also considers the likely length (duration) and frequency of the exposure.
If exposure was or is possible, ATSDR then considers whether chemicals were or are present at levels that might be harmful to people. ATSDR does this by screening the concentrations of contaminants in an environmental medium against health-based comparison values. Comparison values are chemical concentrations that health scientists have determined are not likely to cause adverse effects, even when assuming very conservative/safe exposure scenarios. Because comparison values are not thresholds of toxicity, environmental levels that exceed comparison values would not necessarily produce adverse health effects. If a chemical is found in the environment at levels exceeding its corresponding comparison value, ATSDR examines potential exposure variables and the toxicology of the contaminant. ATSDR emphasizes 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.
After an initial review of potential health hazards at the Fort Devens site, ATSDR identified the groundwater, surface water/sediment, food chain, and indoor air exposure pathways as requiring further evaluation. Following the strategy outlined above, ATSDR examined whether human exposure to harmful levels of contaminants via these pathways existed in the past, exists now, or could potentially exist in the future. ATSDR summarizes its evaluation of potential exposure pathways in Table 3 and describes it in more detail in the discussion that follows. To acquaint readers with terminology used in this report, a list of comparison values and a glossary are included in Appendices A and B, respectively. In addition, Appendix C presents the methods and assumptions used to estimate exposures and support some of the report's conclusions.
After a detailed review of drinking water sources and environmental monitoring data, ATSDR has concluded that no apparent public health hazards are associated with past or current uses of groundwater-supplied drinking water sources. The Army, MADEP, and EPA will continue to take precautions and test groundwater to protect the underlying aquifer and prevent contaminants from reaching drinking water supplies in the future.
Groundwater is the primary source of drinking water for Fort Devens and the surrounding communities of Ayer, Harvard, Lancaster, and Shirley. Fort Devens has relied on on-site drinking water from four groundwater-supplied drinking water wells or wellfields. These wells/wellfields include: the MacPherson well located on the North Post; the Fort Devens Grove Pond wellfield, the Patton well, and the Shebokin well (the primary supply well) situated on the Main Post; and Well D-1 located at the South Post. Unlike the other drinking water wells, the Fort Devens Grove Pond wellfield actually comprises eight individual wells that are connected via a single pumping system. Currently, this wellfield supplies only a small portion of the drinking water supplied to the Fort Devens community since it operates at only one-fifth of its full capacity (MADEP, 1999a). According to the Reuse Plan, the wells on the Main Post and North Post will continue to be used in the future for drinking water, and Well D-1 will continue to be used by the military as a drinking water supply for troops training in the area (Ecology and Environment, Inc., 1994). There are no plans to install new drinking water supply wells on either the Main or North Post, although existing wells could be expanded to meet anticipated water demand.
Communities surrounding Fort Devens also rely on groundwater for public drinking water supplies. Table 2 describes the years of operation, the location, and use pattern for public drinking water wells located in Ayer, Harvard, Lancaster, and Shirley. Of these wells, Ayer's Grove Pond wells are nearest to the Fort Devens boundary, located just beyond the site's northern boundary.
Some people in the area of Fort Devens rely on private wells. A complete inventory on the location and use pattern of private wells in the vicinity of Fort Devens is not available. In discussions with town representatives and following a review of private well registration information, ATSDR learned that no private wells exist in or immediately downgradient from contaminated on-site areas (Harvard Water Department, 1998; Shirley Water District, 1998; Lancaster Water Department, 1998; ADPW, 1998a; Ayer, 1998). It should be noted that several new homes with private wells are located upgradient from a source of groundwater contamination known as AOC 50. We discuss the potential health consequences of contamination at AOC 50 later in this PHA.
As a result of past site activities various chemicals have been released to soil and subsequently to groundwater underlying the Fort Devens property. The Army has collected groundwater samples at many of the AOCs and study areas on Fort Devens to determine where chemical contaminants are located and where they might move. Samples were analyzed for a wide variety of chemicals suspected to have been used at Fort Devens, including VOCs and metals. Selected samples were also analyzed for explosives, pesticides, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs).
In general, VOCs and metals were widely distributed and present in the highest concentrations, whereas explosives, pesticides, and PCBs were much less common in groundwater beneath the post. Table 4 summarizes the results of groundwater monitoring data for VOCs and metals. For each contaminant, the table presents the maximum concentration, the location of that detection, and the most conservative comparison value. As the table indicates, some of the highest levels of VOCs and metals were found in groundwater samples collected at Shepley's Hill Landfill (AOCs 4, 5, and 18) located in the northern portion of the Fort Devens property; the former World War II [WW II] Fuel Points) (AOC 50) located on the northeastern boundary of Moore Army Air Field; and the Historic Gas Station Site (AOC 43G) located in the central portion of the Main Post (see Figure 1). In these areas, several VOCs (i.e., tetrachloroethylene [PCE], 1,2-dichloroethane) and metals (i.e., arsenic, chromium, aluminum) exceeded health-based comparison values. Since detecting groundwater contamination in these areas, the Army has removed or is controlling contaminated sources, and they have started long-term groundwater monitoring programs.
Most of the groundwater contamination appears to be contained on the Fort Devens property. Recent monitoring data, however, indicate that some contaminants have migrated with groundwater beyond the Fort Devens property at the Moore Army Air Field (AOC 50). PCE has entered the groundwater beneath the Army's former Parachute Rigging Facility at the Moore Army Air Field, where the chemical was stored in drums. Although the general direction of groundwater flow in this area is to the southwest, PCE has been transported northward, reportedly as a result of backflow (MADEP, 1998b). The PCE contamination has spread across Route 2A to the Merrimack Warehouse property, where concentrations exceed ATSDR's conservative comparison value for cancer (i.e., cancer risk evaluation guide [ CREG]) but are below EPA's Maximum Contaminant Level (MCL) of 5 parts per billion (ppb). (See Appendix A for a description of CREGs and MCLs). Contamination has not spread further north beyond the warehouse property where residential properties are located (Oakhurst Street). In fact, no detectable concentrations were found in potable wells at the Massachusetts Game Farm located north of the source area or even in monitoring wells far north of the source area and closest to residential areas (MADEP, 1999a). The Army installed a soil vapor extraction system as part of an interim removal action to control the source of PCE contamination (MADEP, 1998b). Between 1994 and 1996, the system removed approximately 240 pounds of PCE from soil.
The Army, with MADEP and EPA oversight, continues to track contamination north of AOC 50 through their extensive network of groundwater monitoring wells. In the fall of 1998, the Army drilled more monitoring wells in the area between the suspected source and the new residential property to the north. These monitoring wells will help to clarify the extent of PCE contamination associated with AOC 50. They also continue to evaluate options aimed at reducing the PCE contamination in the groundwater associated with AOC 50.
The discussion that follows presents information on the potential for exposure to contaminated groundwater through the area drinking water supplies identified above.
Fort Devens Drinking Water Supply (On-site)
Past and Current Exposure
No exposure has occurred through use of water supplied by these on-site wells, primarily because contaminants associated with Fort Devens have never reached areas where any of the Main Post or North Post drinking water wells are located. Furthermore, water from each well is tested quarterly for compliance with state and federal drinking water quality standards to ensure its safety, chlorinated, and then delivered to a central area where it is co-mingled with water from other drinking water wells (MADEP, 1999a; Fort Devens, 1999a).
ATSDR previously evaluated potential health hazards associated with exposure to contaminated groundwater beneath South Post and use of Well D-1 in its 1994 health consultation (ATSDR, 1994). From that evaluation, ATSDR concluded that the explosive contamination in Fort Devens South Post is not a threat to human health because no one drinks water drawn from the contaminated area. A 1996 record of decision (ROD) for the South Post recommended that no further formal remedial action was needed to ensure protection of human health, but the Army is committed to assessing the groundwater quality through long-term monitoring (Horne Engineering Services, Inc., 1996).
The on-site wells will continue to be used for drinking water in the future. Most of these wells are not likely to be threatened by contamination in the future because they do not currently lie in or downgradient from areas of contamination. Furthermore, many measures to protect the groundwater entering these drinking water supply wells are being considered as a major goal in the reuse planning efforts. For example, development of areas overlying the aquifer will be protected through a variety of measures outlined in a Water Resource Protection provision contained in the Reuse Plan Bylaws. MADEP concurs with the provisions as outlined in the reuse plan (MADEP, 1999a). Specific measures in the Bylaws include best management practices for operations on the property and continued monitoring and regulatory control of the aquifer (Vanasse Hangen Brustlin, Inc., 1994). These efforts should help to ensure that the water supply is protected from contaminants in the future.
Although no new wells are planned, the capacity of a given well may be increased to meet anticipated water demands. So far, the Patton well is slated for expansion. The Patton well is located about 600 feet from the Cold Spring Landfill (AOC 40), and the landfill sits within the well's recharge area. Under current pumping conditions, the Patton well is not affected by debris or contamination in the landfill. However, groundwater modeling indicates that when the well is pumped continuously near its capacity of 1,000 gallons per minute, contaminants from the landfill could migrate to the Patton well. If this were to occur, material from the landfill could pose a potential threat to the drinking water supply in the future. A ROD recommending excavation of the landfill (as wells as excavation of AOC 9 and 11 and study area 13, with limited removal of contaminated surface soil at AOC 41 and study areas 12) was signed in July 1999 (Devens Commerce Center, 1998; EPA, 1999; BRAC, 1999).
Public Drinking Water Supplies (Off-site)
The majority of public water supply wells are not at risk of contamination because they are not within or downgradient from areas of contamination. In addition, public water suppliers, under MADEP requirements, ensure the quality and safety of their drinking water through routine testing. The Ayer Grove Pond wells are, however, located just north of Fort Devens. Ayer residents have expressed concern about the proximity of the Ayer Grove Pond wells to the AOCs at Fort Devens, the closest of which are AOCs 44 and 52, about 2,500 feet away. In the particular, residents voiced concern about potential impacts from the Shepley's Hill Landfill, located about 3,500 feet away from the wells (see Figure 4). Because of this concern, ATSDR conducted a focused evaluation on potential harmful exposure associated with use of the Grove Pond wells. The findings of this evaluation were released in a health consultation in July 1998 and are summarized in discussion that follows.
The Ayer Department of Public Works used the Grove Pond wells in the past to supplement water drawn from wells at Spectacle Pond. Grove Pond wells were taken out of service in 1993 after numerous instances in which iron, manganese, and arsenic were detected. While the source of these metals is not known with certainty, it is very likely that they are at least in part naturally occurring for the geographic region (MADEP, 1999a). The wells were placed back in service in 1998. Because the wells were closed between 1993 and 1998, exposure to contaminants, if any, in Grove Pond wells could not have occurred during that time.
ATSDR reviewed the MADEP files to gather available water quality data to determine if unhealthy levels of chemicals existed in the water supply prior to 1993. Complete sampling data for all operating years prior to the 1993 shutdown of the Grove Pond wells are not available, however.(1) It is therefore unclear for how long Grove Pond wells contained iron, manganese, and arsenic and at what levels. Sampling data collected sporadically since the 1960s indicate that iron and manganese levels in raw water often exceeded the current secondary MCLs for aesthetic quality (e.g., taste, color, and/or odor properties) (CDM, 1968, 1993; SEA Consultants, Inc., 1990).(2) After 1978, however, raw water from the Grove Pond wells, when operating, was then co-mingled with Spectacle Pond well water, thereby diluting contamination, if any, in the Grove Pond well water before it reached residential taps (ADPW, 1998a). All other contaminant concentrations were safely below safe drinking water standards.
Both manganese and arsenic are known to cause health problems at high enough levels, but iron is rarely toxic to humans. In evaluating potential health hazards associated with drinking water containing manganese and arsenic, ATSDR estimated the dose of these metals an individual might have received using site-specific considerations and conservative assumptions about how often people drink water and how much water they drink. ATSDR also assumed that an individual drank water containing the highest detected concentrations of manganese and arsenic in well water. This is a highly conservative and unlikely scenario because often the water was blended and/ or treated before use by the consumer.
ATSDR then compared the estimated exposures to acceptable health guidelines to determine the likelihood, if any, that Ayer residents could have been exposed to harmful levels of manganese or arsenic in their drinking water. This evaluation is described in greater detail in Appendix C. The results of the evaluation indicate that the estimated exposure doses for Ayer residents are below levels at which health effects have been reported in the toxicologic literature, even when assuming exposure to the maximum detected contaminant concentrations. ATSDR therefore concluded that Ayer residents have not been exposed to harmful levels of contaminants when they used water originating from the Grove Pond wells in the past.
Following a formal evaluation of the water treatment system and a permitting process, the Ayer Department of Public Works resumed production at the Grove Pond wells during in the summer of 1998. For several weeks after startup, EPA, MADEP, and the Ayer Department of Public Works closely monitored the effectiveness of the new system and the quality of its water. They found that by treating the raw water for iron, manganese, and arsenic, and then blending the treated water with water from Spectacle Pond wells, they produced finished drinking water that safely met drinking water standards. Since the Grove Pond wells have come back on line, testing by both the EPA and Ayer Department of Public Works has shown that the public water supply has safely met drinking water standards (ADPW, 1998a; 2000). Under the guidance of the states drinking water program, Ayer Department of Public Works will continue to monitor routinely VOCs and inorganic compounds (e.g., arsenic, manganese, iron). ATSDR has concluded that Ayer residents are not exposed to harmful levels of contaminants when drinking water from the Ayer public water supply.
During the 5-year review of the Shepley's Hill Landfill, it became evident that seeps containing leachate had formed nearby. Leachate is water that enters the landfill as precipitation and becomes contaminated as it moves through the decomposing refuse. Community members expressed concern about leachate discharging into local surface water bodies, such as Plow Shop Pond, or into deeper groundwater, and eventually reaching drinking water supplies. ATSDR also identified five AOCs/SAs that lie within the Zone II area of influence for the Grove Pond wells (see Figure 4), to identify potential future hazards. As defined by MADEP, a Zone II area of influence "...is the area of groundwater contribution to the wells under the most extreme severe pumping and recharge conditions." The sites in the Zone II include the Battery Repair and Storage Area (study area 38), the Maintenance Yards (AOCs 44 and 52), the Plow Shop and Grove Ponds (study area 72), Lower Cold Spring Brook (study area 73), and the Massachusetts National Guard property, a site located between Fort Devens property and the wells (NEET, 1997).
ATSDR closely evaluated information on Shepley's Hill Landfill and the five sites within the Zone II area of influence for evidence of potential future threats to the Grove Pond wells, and concluded that they are not likely to affect the quality of drinking water. This conclusion is based on the following observations:
- The Shepley's Hill Landfill is outside the Zone II area of influence. Although Shepley's Hill Landfill has high concentrations of groundwater contaminants (primarily VOCs and arsenic), the landfill is unlikely to influence the groundwater entering the Grove Pond wells because it is located outside the Zone II area of influence and water passing through the landfill moves to the north and east and away from the Grove Pond wells. Furthermore, the Army will take measures to ensure the quality of the aquifer that lies beneath the site and to monitor possible contaminant migration.
- The Battery Repair and Storage Area, the Maintenance Yards, Lower Cold Spring Brook, and the Massachusetts National Guard property have no or very low levels of groundwater contamination. Any existing low level contamination is unlikely to reach the Grove Pond wells. Furthermore, the Army has removed the contaminated source material (e.g., contaminated soil), thereby reducing the likelihood of contaminant migration from these areas in the future.
- Grove Pond and Plow Shop Pond are expected to have minimal impacts, if any, on the wells in the future. EPA is collecting data on how much groundwater recharge from the ponds enter the drinking water wells. ATSDR will evaluate the relationship between the ponds and the wells when this information becomes available.
On the basis of this information, ATSDR has concluded that residents will not be exposed in the future to harmful levels of contaminants when drinking water that comes from the Grove Pond wells.
Private Wells (Off-site)
Past, Current, and Future Exposures
No contamination has spread to areas where private wells exist. As previously mentioned, PCE has moved from the former Parachute Rigging Facility at AOC 50, but the contamination has not moved further north to where new private wells are located (Ayer, 1998; Fort Devens, 1999b). The MADEP, EPA, and Army will continue to track groundwater contamination and take actions to further reduce any potential effects on off-site areas with existing private wells. At this time, a groundwater study, undertaken by the Army with EPA and MADEP oversight, is pending. ATSDR concluded that area private wells users are not exposed, nor have they been in the past, to site-related contaminants when using their well water. MADEP, EPA, and the Army continue to take precautions and track contamination in areas near off-site private wells to limit the potential for future exposures.
No harmful exposures have occurred in the past, nor are likely to occur for people who wade, boat, or catch and release fish, at Grove Pond and Plow Shop Pond. As a precautionary measure, advisories currently recommend against swimming at either pond.
The community surrounding Fort Devens has used Grove Pond and Plow Shop Pond for recreational uses in the past. A "catch and release fishing only and no swimming advisory" has been posted at the ponds because of concerns about contamination in pond sediment and surface water. In response to community concern, ATSDR evaluated potential public health hazards from recreational uses of Grove Pond and Plow Shop Pond in a health consultation released in December 1998. In the discussion that follows, ATSDR summarizes the findings of that focused evaluation.
Grove Pond and Plow Shop Pond Description and Uses
Grove Pond and Plow Shop Pond are shallow water bodies located along Fort Devens' northern boundary (see Figure 5). Grove Pond, once known as the Tannery Pond, is a 60-acre pond that receives inflowing water from Balch Pond and Cold Spring Brook. Water from Grove Pond flows through a stone arch culvert beneath a railroad causeway and into Plow Shop Pond, so named for the Ames Plow Foundry formerly located at the pond. Plow Shop Pond, the smaller of the two ponds (30 acres), receives most of its water from the upstream Grove Pond. Water from Plow Shop Pond eventually discharges from a dam at the northwest corner of the pond to Nonacoicus Brook, which flows about 1 mile north before joining the Nashua River (ABB, 1995).
Land use surrounding the ponds is diverse. Property along Grove Pond includes a mix of residential (along the northern shore), recreational (Pirone Park), and industrial, including an active railyard and a former tannery. The tannery operated between the mid-1900s and the 1960s in the northeast corner of Grove Pond (east of the railroad). Until 1953, the tannery reportedly discharged much of its process wastewater into Grove Pond, often with little or no treatment. While the former tannery was once a source of metal contamination for the pond, the findings of a joint 1997 EPA and MADEP removal site evaluation indicate that it no longer poses an imminent threat to either human health or the environment. Plow Shop Pond is largely surrounded by industrial property. Over the years, the industrial uses included railroad operations to the east, an industrial park to the north, and Fort Devens' Shepley's Hill Landfill area to the west and southwest (ABB, 1995).
Grove Pond and Plow Shop Pond might have been used in the past for recreational activities, but today, little, if any, swimming or subsistence fishing is believed to occur at either pond (ADPW, 1998b). In 1992, the Army posted an advisory at Plow Shop Pond recommending that people not swim in the pond or eat pond fish. The Army took this precautionary measure because of concerns about contaminants in pond sediment and the possibility that these contaminants were accumulating in fish (ATSDR, 1992). Following this action, ATSDR advocated that similar precautions be followed for uses of the adjacent Grove Pond (ATSDR, 1992). It should be noted that people can still enjoy boating and catch and release fishing at both ponds.
In informing the community about the advisory, the Army coordinated outreach with other agencies (e.g., ATSDR, MDPH, MADEP, EPA, and local boards of health) and abutting landowners, including the B & M railroad. The advisory was also posted at key access points to each pond. The EPA is responsible for providing replacement signs, and the Ayer Department of Public Works and MassDevelopment are responsible for maintaining the signs along the ponds in the future (ADPW, 1998b). In addition to the postings, information on these advisories (and all Massachusetts fish consumption advisories) is summarized by MDPH and distributed with Massachusetts fishing licenses by the Massachusetts Division of Fisheries and Wildlife.
Grove Pond and Plow Shop Pond Surface Water and Sediment Quality
The Army conducted several rounds of surface water and shallow sediment sampling to characterize the environmental conditions of Grove Pond and Plow Shop Pond. Samples were collected from the interior of each pond and along shoreline areas. Samples were analyzed for metals, and selected samples were analyzed for pesticides, PAHs, and PCBs. ATSDR examined the sampling data and compared this information against current ATSDR comparison values to identify contaminants of potential health concern.
Table 5 summarizes surface water sampling results for both ponds. As the table indicates, the metals arsenic, chromium, lead, and manganese were present in pond surface water. Arsenic, chromium, and lead were found in only a few of samples, and rarely at levels above ATSDR comparison values for drinking water. Manganese was present in every sample, at times at levels (up to 130 ppb) above its drinking water comparison value for a child (50 ppb), but most often at levels below the comparison value.
Table 6 shows chemical concentrations measured in sediment samples collected from both Grove Pond and Plow Shop Pond. (3) The table also specifically indicates to what extent these chemicals were present in the sediment samples taken from the Grove Pond shoreline at Pirone Park. This area is of interest to ATSDR and the community since children visit the park and concentrations detected near the park most directly reflect the levels to which children could be exposed.
According to the sampling data, sediment samples taken from both ponds contained elevated levels of arsenic, cadmium, chromium, lead, manganese, and mercury. The highest levels of these metals were generally noted in the interior of Grove Pond and Plow Shop Pond or along the shoreline of nonpublic areas. In these areas, arsenic, cadmium, lead, and manganese concentrations exceeded ATSDR's comparison values or EPA's interim screening values for soil. Chromium and mercury were also measured in sediment, but no comparison values for sediment or soil currently exist for these chemicals. Along the shoreline of Pirone Park, where people are more likely to frequent, arsenic (up to 110 ppm) and cadmium (up to 23.3 ppm) concentrations were sometimes measured at levels higher than their respective comparison value for a child, but most often were lower.
Distribution patterns for several contaminants found in Grove Pond sediment provide some indication of their potential source. Chromium, used in tannery operations, was the most frequently detected contaminant and was found in the highest concentrations in sediment along the northwest cove of Grove Pond, where the former tannery once stood. Arsenic, manganese, and mercury were distributed similarly to chromium, suggesting the tannery is likewise a source of these metals. In contrast, however, distribution of metals in Plow Shop Pond sediment showed no clear pattern and varied by chemical. Historical sources of contamination in Plow Shop Pond include Shepley's Hill Landfill (e.g., arsenic, iron, manganese), railroad activities (e.g., PAHs and mercury), and inflow from Grove Pond (e.g., arsenic) (ABB, 1995). It is also suspected that the tannery directly discharged materials to Plow Shop Pond via a pipe under the railroad track (Fort Devens, 1999a).
PAHs were also detected in sediment, but they were not nearly so widespread nor in as high concentrations as metals. Most PAHs were located near the railroad corridor and are likely associated with railroad activities (ABB, 1995). Concentrations of individual PAHs were generally comparable to the comparison value (0.1 parts per million [ppm]) for the PAH compound, benzo(a)pyrene.(4) Other tested compounds (i.e., PCBs, pesticides) were either not detected or were detected at concentrations below comparison values.
The infrequently occurring elevated levels of metals found in surface water or sediment along public areas, such as Pirone Park, would not have harmed the health of people who used the park for wading, boating, and catch-and-release fishing. The highest levels of contaminants were detected in the interior of the pond or near the tannery. We do not have evidence that people swam in the portions of the pond where higher levels of contaminants were found. If people did access these areas, their infrequent and brief exposure to the most contaminated sediment is unlikely to have caused adverse health effects. For this reason, no exposure is likely to have occurred in the past at levels causing public health concern.
Current and Future Exposures
ATSDR did not find any indications that people use or will use either pond for recreation in ways that would result in significant dermal contact with harmful levels of chemicals (i.e., swimming). Nonetheless, as a precautionary measure, an advisory posted at Grove Pond and Plow Shop Pond recommends against swimming at either pond. In response to ongoing community concern about exposure, particularly for children, however, ATSDR further evaluated exposure that might occur while a person wades along the shoreline where the highest levels of contaminants were detected, as well as exposure that might occur in public areas, such as Pirone Park.
When evaluating this potential exposure pathway, ATSDR estimated how much of a particular metal an individual might contact and absorb. To do this, ATSDR developed exposure doses for dermal contact with sediment based on conservative or "safe" scenarios and compared these doses to the health-based guidelines. ATSDR selected for further evaluation arsenic, cadmium, chromium, and mercury because they either were measured at levels above comparison values or they currently lack a comparison value. In estimating exposure ATSDR assumed that an individual might wade at the pond or visit Pirone Park every day during warm months (i.e., 140 days a year) over the course of many years (i.e., up to 30 years for an adult or 6 years for a child). Appendix C describes the methods and assumptions used in ATSDR's evaluation in greater detail. The results of the comparison indicated that estimated exposure doses were all below ATSDR noncancer and cancer health guidelines, or below levels at which adverse health effects have been reported. Moreover, the chemicals found in the sediment are not likely to pose a health problem because they are not readily absorbed through the skin and are not present in very high concentrations in public access areas. Therefore, contact with pond sediment poses no health hazards to adults or children who might wade along the shoreline of Grove Pond or Plow Shop, even when assuming contact with highest detected contaminant concentrations frequently (140 days a year) over an extended period of time.
Mercury has been found in fish collected from Plow Shop Pond, Grove Pond, and Mirror Lake. As a precautionary measure, health officials are advising residents to limit or refrain from eating fish caught from these water bodies. People can best protect themselves by continuing to follow the recommendations in the advisory posted at each water body.
Mirror Lake, Grove Pond, and Plow Shop Pond are water bodies where people enjoy recreational fishing. As mentioned, fish consumption advisories posted at these water bodies, however, advise people to limit (Mirror Lake) or refrain from eating fish (Grove Pond and Plow Shop Pond). In the discussion that follows, ATSDR presents its evaluation of fish sampling data collected for these water bodies to determine whether contaminant concentrations, if any, in fish indicate a public health concern or whether additional protective measures need to be taken.
Fish Monitoring Data
Three sampling programs have collected fish samples from Grove Pond, Plow Shop Pond, and Mirror Lake, and analyzed fish samples for metals, pesticides (i.e., 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene [DDD], 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane [DDE]), and PCBs.(5) The three programs include:
- The Army collected 15 fish samples (bluegills, largemouth bass, and brown bullheads) from Plow Shop Pond in 1992 (Fort Devens, 1995b). The detection of high levels of chemicals in pond sediment and concern about the possibility that fish were accumulating the chemicals led to this investigation.
- The U.S. Fish and Wildlife Service collected 28 fish samples (largemouth bass, bluegill, brown bullhead, and yellow bullhead) from Grove Pond in September 1992 (U.S. F&W, 1993; 1997). Likewise, this investigation was prompted by concerns about high levels of pond sediment contamination.
- The MADEP collected 18 fish from Mirror Lake in June 1995. MADEP collected the fish samples as part of its obligation under the Massachusetts Interagency Fish Toxics Program (MADEP, 1995).
Tables 7, 8, and 9 provide the fish sampling results for Grove Pond, Plow Shop Pond, Mirror Lake, respectively. ATSDR reviewed these sampling data to determine what chemicals, if any, had accumulated in fish.
- Grove Pond and Plow Shop Pond: Metals, PCBs, and pesticides were present in fish samples collected from one or both of these ponds. ATSDR compared the fish tissue concentrations to available Food and Drug Administration (FDA) action levels for commercial fish. Action or tolerance levels are available for mercury, PCBs, and some pesticides (e.g., DDD and DDE) only. As Tables 7 and 8 indicate, mercury exceeded its FDA action level (1 milligram per kilogram [mg/kg]) in a largemouth bass, while concentrations of other compounds (i.e., PCBs, DDD, and DDE) for all fish were safely below their respective FDA action or tolerance level.(6) Mercury found in fish from these ponds is probably associated with the low-level mercury-contaminated sediment found near the tannery and the railroad area. The findings of the sampling supported the existing precautionary fish consumption advisory.
- Mirror Lake: Metals were present in fish samples collected from Mirror Lake, but PCBs and pesticides were not detected. Mercury concentrations were below the FDA action level, but the average concentration of mercury in all largemouth bass was above the Massachusetts Department of Public Health's (MDPH) level of 0.5 mg/kg for issuing a limited advisory. On the basis of this finding, the state issued a limited advisory recommending that the general public limit their consumption of largemouth bass from Mirror Lake to two meals per month and that sensitive individuals (e.g., children, pregnant women) avoid affected Mirror Lake fish.
It should also be noted, however, that mercury is a widespread problem in Massachusetts' and many other states' freshwater rivers, ponds, and lakes. As a precautionary measure, MDPH issued a statewide advisory in September 1994 to urge pregnant women not to eat fish caught from freshwater bodies in Massachusetts because of the potential harmful effects of mercury on the fetus (MDPH, 1995).
Although mercury was detected at concentrations greater than the FDA action level, consumption of pond fish containing this level of mercury would not necessarily result in adverse health effects. To further evaluate this exposure pathway, ATSDR estimated exposure doses considering site-specific parameters and the maximum concentrations of contaminants detected in pond fish (see Appendix C, Tables C-4 and C-5). ATSDR then compared the doses to health-based guidelines. Although the estimated dose for a child slightly exceeded ATSDR's health-based guidelines, health effects are unlikely to occur. First, a number of safety factors have been applied to the ATSDR health-based guidelines, as a result estimated doses above these guidelines would not necessarily produce health effects. Second, the estimated exposure dose probably overestimates the actual exposure a child might have received because the likelihood that a child frequently consumed the most contaminated fish for extended periods is remote. Furthermore, with the exception of a few samples of largemouth bass, most mercury concentrations were below the FDA action level. Therefore, ATSDR has concluded that no harmful exposures to mercury or other contaminants are likely to have occurred in the past for people who ate fish from either Grove Pond, Plow Shop Pond, or Mirror Lake.
Current and Future Exposures
Currently, advisories recommend that people not eat fish or limit their consumption of fish caught from either Grove Pond, Plow Shop Pond, or Mirror Lake. Because mercury is persistent in the environment, levels in fish may have increased since the initial fish sampling. Therefore, as a precautionary measure, people should continue to follow the recommendations in the advisory until additional data suggest otherwise. The Ayer Department of Public Works and MassDevelopment have agreed to maintain the signs provided by EPA at Grove Pond and Plow Shop Ponds. Therefore, no public health hazards are occurring now, nor are they expected to occur in the future for people who follow the recommendations in the advisory.
Air inside the former Devens Elementary School poses no current or future public health hazards from contaminants associated with historic fuel oil spills. Available indoor air monitoring indicates that no fuel contaminants have been found inside the school at levels of health concern.
In 1972 and again in 1978 fuel oil No. 2 was accidentally released into the subsurface soils and groundwater adjacent to and beneath the Devens Elementary School (AOC 69W), located on the northwest portion of the Main Post. The release was assumed to be from damaged piping near and within the footprint of the school (EPA, 1998). Since 1993, the Army has closed the school for reasons unrelated to the release, removed the damaged piping along with 3,500 cubic yards of contaminated soil, and MassDevelopment has converted the heating system to a gas-based operation (MADEP, 1999a; MassDevelopment, 2000). Teachers and other community members raised concerns about the release and whether contaminants associated with the release had or could affect the air inside the school.
In 1998, the EPA collected air quality data to determine if fuel-related contaminants present in the soil and groundwater were migrating up through the soil and into the school.(7) Eleven samples were collected at the following locations: six in various rooms throughout the school; three outdoors; one in the crawlspace near the old boiler room; and one in the crawlspace beneath the kitchen. Samples were analyzed for components of fuel oil found in the soil and groundwater, primarily VOCs and semivolatile organic compounds.
Of the compounds analyzed for, methylene chloride was the only compound detected at levels above air guidelines. Methylene chloride is not a constituent of fuel oil No. 2, but it is often present as a common laboratory contaminant. Therefore, the presence of methylene chloride in the samples is probably not related to the spill, but likely resulted from decontamination procedures used to clean the air sampling tubes (ATSDR, 1995). No other compounds were detected at levels of health concern.
The only available air data comes from a one-time 8-hour samples collected during the spring of 1998. These data provide only a "snapshot" of actual conditions that might have existed since the release. Because of these data limitations, ATSDR cannot conclusively determine whether harmful levels of contaminants were present inside the school while it was open. Based on recent air monitoring data, however, there does not appear to be any evidence that contaminants from the oil spill exist in the school. If similar conditions existed around the time following the release, it is unlikely that harmful exposures have occurred.
Some community members were particularly concerned about breast cancer among teachers and a possible link to the release. To date, no studies have examined breast cancer in former occupants of the school, but MDPH's review of health outcome data indicates that breast cancer rates are not elevated in the community of Ayer. Although these data are not specific to the school, the information is indicative of the general health of the population of the surrounding community, where occupants of the school might reside.
Current and Future Exposures
The school has been closed since 1993 and therefore no exposures are currently occurring. Although the school is scheduled to reopen in 2000, ATSDR believes that the indoor air is unlikely to pose health threats to future occupants for the following reasons: 1) current air monitoring data suggest the air meets safe air quality guidelines and 2) the Army has removed most of the fuel-contaminated soil associated with the releases.(8) The EPA has determined that no further actions are needed to clean up soil contamination, but they will oversee long-term monitoring of groundwater in the area.
The following discussion evaluates community health concerns. This public health assessment states each concern and presents a brief summary of ATSDR's conclusions. ATSDR also received comments and questions from community members regarding the draft PHA for the Fort Devens site (June 1999). Responses to comments received during the public comment period are addressed in Appendix D of this PHA.
- Concern about tumors in domestic animals in the community around Fort Devens and their relevance to humans.
Scientists consider many factors when evaluating the likelihood of developing cancer. One such factor is species-specific sensitivity or response to a potential carcinogen. It should be noted that an animal's response to a carcinogen is dependent not only on its species-specific biochemical makeup but on physiological and anatomical features as well. Therefore, mechanisms that lead to cancer or tumor development in domestic animals may not exist for humans.
MDPH monitors human cancer incidence in Massachusetts communities. MDPH reviewed the most recent available information (1982-1992) from the Massachusetts Cancer Registry for the town of Ayer (MDPH, 1997). For the time period of 1982 to 1992, the cancer incidence in Ayer was approximately equal to or just slightly higher (but not statistically higher) than expected for the majority of cancers. On the basis of this review, the MDPH concluded that there does not appear to be an unusual occurrence of cancer in Ayer.
Community members who would like more information about cancer rates in other communities surrounding Fort Devens or would like to express their concerns should contact the Massachusetts Department of Public Health at 617-624-5757.
- Concern that rates of breast cancer are slightly higher than normal among former teachers of the former Devens Elementary School.
Several risk factors have been associated with breast cancer, including life style, genetic factors, and, even to a certain extent, environmental factors. In pursuing a possible environmental link, ATSDR first examines exposure pathways related to a site of concern. If ATSDR determines that a completed exposure pathway poses a public health threat, ATSDR then gathers health outcome data to complement the environmental and exposure data.
ATSDR did not identify any completed exposure pathways linking air contaminants associated with the fuel spill to the school occupants. Given this finding, we do not have reason to suspect that the spill adversely impacted air or that teachers were exposed to contaminant levels that could adversely affect their health or increase their likelihood of developing cancer. MDPH's review of health outcome data for the community of Ayer indicated that breast cancer rates were not elevated. While not specific to teachers at the school, this information is indicative of the breast cancer experience of the population of Ayer, where some of the occupants of the school may reside.
For individuals concerned about breast cancer occurrence, you should know that the Massachusetts Department of Public Health has compiled information about risk factors for breast cancer. A copy this information can be obtained by calling 617-624-5757.
- Concern about a link between manganese in drinking water and attention deficit disorder among Ayer school children.
Some community members of Ayer are concerned about a possible link between drinking water containing manganese and attention deficit disorder among school children. As discussed in the "Evaluation of Potential Environmental Pathways" section of this document, the Ayer Grove Pond well water contained elevated levels of manganese (up to 1,900 ppb) before it was closed in 1993. Despite high levels of manganese in these wells, it is unlikely that people were actually exposed to these levels because water from these well was blended with uncontaminated water prior to distribution to households. Also, levels of manganese fluctuated over time and were generally much lower than maximum levels while the wells were used for drinking water. Since reopening the wells in 1998, the Ayer Department of Public Works has treated the well water to ensure that high quality water is delivered to consumers.
Manganese is a naturally occurring element that is essential for normal functioning of the human body. There are many reports of human toxicity from exposure to manganese by inhalation; however, ingested manganese has rarely been associated with toxicity. One reason for this may be that very little manganese is taken up by the stomach and absorbed into the body. Human health studies suggest that ingesting high levels of manganese in drinking water over a long period of time may be associated with neurological changes resembling Parkinson's disease (Kawamura et al., 1941; Kondakis et al., 1989; Goldsmith et al., 1990). Although the findings suggest that environmental exposure to high levels of manganese may be a health concern, there are just too many limitations to these studies to provide conclusive evidence. It should be noted that the exposure doses estimated by ATSDR for persons ingesting water from the Ayer Grove Pond wells were almost 15 times lower than adverse effect levels reported in these studies.
There is some concern by scientists that infants may be at increased risk of toxicity from manganese ingestion because infants take up manganese from the stomach at a higher rate than adults and they have less ability to excrete manganese from the body. To date, there are no reports of manganese toxicity, including attention deficit disorder, reported for infants. Again, the exposure doses ATSDR estimated for children and adults who may have ingested water from the Ayer Grove Pond wells are within ranges of "safe dietary intakes" and are lower than levels shown to cause even adverse effects (including neurological effects) in scientific studies. ATSDR has evaluated exposure to manganese in greater detail in Appendix C of this document.
Over the past decade, scientists have explored a number of possible theories about what causes the attention deficit disorder, but researchers at the National Institute of Mental Health stress that the cause is still not known. While much of the evidence from recent investigations suggests that the disorder stems from biological causes rather than from factors in the home environment, scientists continue to investigate possible causes of the disorder.
- Concern about safety hazards from unexploded ordnance at the South Post.
The South Post has been used as a training range for various types of small arms fire, grenade detonation, and ordnance demolition. Unexploded ordnance used in training may still remain buried in sections of this area. As a safety measure, Fort Devens maintains a fence around the South Post Impact Area and posts warning signs to discourage unauthorized access to the South Post. ATSDR agrees with these measures that will help limit public access and improve safety.
- Concern about safety hazards while walking around Mirror Lake.
Historically, World War II grenades were placed in Mirror Lake. In 1965, the 14th EOD Detachment Station at Fort Devens removed the grenades from the lake (BRAC, 1996). It should be noted that the grenades removed from the lake were unfused and contained no explosive charge (MADEP, 1999b). An underwater metal survey confirmed that the removal was complete. Additionally, a 1995 supplemental site investigation indicated that there was no explosive contaminants associated with the grenades in Mirror Lake's surface water or sediment.
- Concern about health hazards for trespassers who may unknowingly contact contaminated media along the shoreline of Grove Pond or Plow Shop Pond.
In all likelihood, people who walk along the shoreline of the ponds are not incurring harmful exposures. People trespassing in nonpublic areas of the shoreline probably do so infrequently and/or for a short period, spending relatively little time standing or walking with exposed skin in areas of the highest contaminated sediment. Limited exposures of this type are not likely to lead to adverse health effects. Most importantly, we doubt that young children (1 to 6 years of age) who are most suspectable to the effects of contaminants would travel into these areas--and come in contact with the most contaminated sediment--without adult supervision.
- Concern that subsistence fishing populations might have consumed harmful amounts of contaminated fish from Grove Pond or Plow Shop Pond in the past.
Subsistence fishing populations rely on freshwater fish as a major staple in their diet. Because they eat so much more fish than most people, there is a concern that they have a greater exposure to potentially harmful levels of chemicals found in freshwater fish of some areas. To date, however, there is only anecdotal information to suggest that few anglers, if any at all, regularly fished for food at either Grove Pond or Plow Shop Pond. As such, it is unclear if subsistence anglers ever relied on either pond for food.
In the "Evaluation of Food Chain Pathway" section of this PHA, we looked at potential health hazards for a more realistic exposure scenario--that is, for someone likely to consume a moderate amount Grove Pond or Plow Shop Pond fish. Based on this evaluation, we determined that consumption of a moderate amount (one meal a month, the average consumption of fish and shellfish from estuarine and freshwaters by the general U.S. population) of Grove Pond or Plow Shop Pond fish was not harmful to either the adult or child consumer.
Because a few people might have routinely eaten Grove Pond and Plow Shop Pond fish, we also considered whether they might be at increased risk of health effects. We found that people who ate as much as seven meals a month (a substantial amount, based on EPA's upper bound value of fish consumption of recreationally caught fish) of Grove Pond or Plow Shop Pond fish still are not likely to develop any harmful health effects. As with the evaluation for moderate consumption of fish, we even assumed that individuals ate fish containing the highest detected concentrations over many years, a highly protective but unlikely scenario.
We hope through the existing fish consumption advisories that any subsistence anglers will become aware of the potential public health hazards of continuing to eat fish from Grove Pond and Plow Shop Pond. In efforts to target groups at risk throughout the state, the MDPH has initiated education and outreach programs to inform the state's medical community (e.g., primary care providers and health clinics) about health concerns relating to consumption of freshwater fish. ATSDR feels that the medical community can assist people relying on potentially contaminated freshwater fish to understand the potential health risks and find healthy alternatives.
- Concern about health hazards from combined risks of exposure to contaminants in sediment, fish, and drinking water.
As stated in this PHA, neither the sediment, fish, or groundwater/drinking water pathways alone pose a public health concern largely because either: 1) exposure was or is unlikely to occur or 2) contaminant concentrations detected were too low to pose a health hazard. As part of our evaluation, we conservatively derived exposure doses for chemicals (at levels above comparison values) in these pathways but found that the values were generally lower than acceptable health-based guidance levels such as minimal risk levels (MRLs) or reference doses (RfDs). It should be noted that MRLs and RfDs are conservative estimates of safe exposure doses that are generally orders of magnitude higher than the lowest levels to which health effects have been observed in occupational or animal studies. With this in mind, we feel that the sum of exposures to contaminants in these pathways should not pose health concerns or adversely impact public health.
- Concern about potential future impacts to off-site groundwater near the South Post Impact Area.
Testing of groundwater underlying the South Post Impact Area has revealed elevated levels of explosive compounds. While no formal remedial action (institutional controls) was deemed necessary to control groundwater contamination in this area, the Army, with EPA and MADEP oversight, developed a long-term monitoring plan in 1997 for the South Post Impact Area. As detailed in the plan, the Army monitors water in the shallow aquifer at discharge points as well as at sentinel wells located near the perimeter. Samples are then analyzed for metals and explosive compounds, and selected samples are analyzed for volatile organic compounds. Monitoring of sentinel wells helps investigators identify contaminants long before they reach area drinking water wells.
- Concern that people living in former base housing or playing in a future school yard could be exposed to harmful levels of pesticides.
Future residents of revitalized housing or children playing at the proposed school yard probably will not be exposed to harmful levels of soil pesticides.
The Massachusetts Development Finance Agency (MassDevelopment) is charged with returning portions of the former Fort Devens site to productive use. Environmental testing at Fort Devens has revealed, however, the widespread and pervasive presence of pesticides in soil (approximately 160,000 cubic yards of soil) beneath former base housing units (MADEP, 1998c). When these units were constructed in the 1960s, the Department of Defense commonly applied pesticides to control termite infestations beneath foundations built on slabs. At Fort Devens, the soil beneath the housing unit slabs was treated with the termiticides aldrin, chlordane, DDT, and dieldrin. Such pesticide applications are not permitted today. Aldrin, chlordane, and dieldrin are chlorinated hydrocarbon pesticides that are particularly persistent in our environment. Even though applications at Fort Devens occurred more than 30 years ago, we would still expect to see measurable levels of these compounds in the soil beneath the slabs.
MassDevelopment proposes either reusing several hundred of these units or demolishing these units and using the land on which they sit to build new structures. Of particular interest to ATSDR is proposed redevelopment of units for housing and other areas for a school.
Birch Circle/Grant Housing
The Birch Circle and Grant Housing areas are located in the northwest portion of the Fort Devens site. MassDevelopment proposes to reuse 282 units for housing, of which approximately 25 percent will be reserved for low-and moderate-income families and persons who have special needs. Soil testing conducted in 1996 revealed soil pesticide concentrations that exceed ATSDR comparison values (CVs). Additional testing of the air quality inside the 300 and 800 series units of the Birch Circle and Grant Housing areas also indicated that pesticides found in soil had entered the units and were present in the indoor air. Aldrin (up to 2.1 micrograms per cubic meter [µg/m3]), chlordane (up 0.15 µg/m3), and dieldrin (up to 1.00 µg/m3) were detected in the indoor air of the 800 series units at concentrations greater than ATSDR CVs (and state and federal guidelines) (Haley & Aldrich, 1998). Breathing air containing these levels of pesticides over an extended time could pose a health concern for future residents. Pesticide concentrations in the 300 series units were found to be within acceptable guidelines.
The higher concentrations of pesticides inside the 800 series units were most likely caused by features of the units' mechanical systems and, to a lesser extent, to the building foundation (TRC, 1999). First, the air-handling systems of these units supply air through ducts beneath the floor--within the pesticide-contaminated soil. Because the ducts pass through the contaminated soil, they may be potential points of entry for contaminants into the units. Second, these units have whole-house fans, which increase the negative pressure and draw air in from soil beneath the slab. Third, the heating systems in these units lack a source of fresh air. In addition to diluting chemicals in indoor air, a fresh air supply would help reduce the negative pressure in the units.
There could be harmful effects to long-term residents in the 800 series units who breathe the highest concentrations of pesticides detected in air inside the units. Because of this concern, ATSDR supports measures that will reduce indoor air pesticide concentrations to safe levels before the units are occupied in the future. According to the MassDevelopment, the units will remain unoccupied until the indoor air quality safely meets standards set by Massachusetts Department of Environmental Protection (MADEP) or the U.S. Environmental Protection Agency (EPA). To date, the MassDevelopment has evaluated several options to improve the air quality within the affected units, including modifications to the mechanical heating systems. The U.S. Army and MassDevelopment are negotiating terms of the cleanup. ATSDR will review the plans to ensure that the modifications will minimize exposures to pesticides inside the units (i.e., achieve air quality that meets ATSDR safety guidelines).
The town of Shirley considered the unoccupied Shirley Base Housing Area as a possible site for a future school. The 22-unit Shirley Base Housing area, also known as the 900 series units, is located to the west of the Main Post, adjacent to the Shirley base entrance gate. Eighteen of the units encompass the area intended for the school. Pesticides to control termites, including aldrin, chlordane, DDT, and dieldrin, were applied to the soil beneath the housing units before the concrete foundations were poured. Because the soil beneath the foundations would be exposed during construction of the new school, Shirley town officials asked ATSDR to evaluate the potential hazards from contact with residual pesticide contamination in soil. ATSDR evaluated this exposure and presented its findings in a September 1999 health consultation. The findings are summarized in the discussion that follows.
ATSDR reviewed soil sampling data collected in 1996, which indicated that aldrin and dieldrin were at levels above ATSDR CVs, while concentrations of the other pesticides were below CVs. Because concentrations of aldrin and dieldrin exceeded CVs, ATSDR estimated potential exposure levels for a child playing in the exposed soil containing the maximum detected levels of these pesticides. The exposure estimates accounted for the ways in which the pesticides could enter a child's body either by ingestion, skin contact, or inhalation of dust. When these exposure routes were combined, the estimated average daily exposures to aldrin and dieldrin were more than two times lower than ATSDR's conservative minimal risk levels (MRLs) for those pesticides. An MRL is an estimated level of daily human exposure to chemicals that are unlikely to pose appreciable risk of adverse noncancer health effects. Therefore, ATSDR believes that no harmful effects are likely to occur in the future. It is important to note that no past or current exposure is possible, because the contaminated soil is under concrete slabs and is inaccessible.
Regulatory agencies involved in cleanup at Devens, such as EPA and MADEP, have established requirements that guide remedial activities. These requirements will be applied to the pesticide- contaminated soil at the housing units, and may necessitate remedial actions that possibly could include removal of pesticide-contaminated soil. Although ATSDR's evaluation found no increased hazard associated with future use of the area proposed for the school yard, the Agency supports any precautionary practices that would further minimize potential exposures to hazardous materials.
ATSDR recognizes that infants and children may be more sensitive than adults to environmental exposure in communities faced with contamination of their water, soil, air, or food. This sensitivity is a result of the following factors: 1) children are more likely to be exposed to certain media like soil when they play outdoors; 2) children are shorter and therefore might be more likely to breathe dust, soil, and vapors close to the ground; and 3) children are smaller than adults and therefore might receive a higher dose of chemical exposure relative to their body weight. Children also can sustain permanent damage if exposed to toxic substances during critical growth stages. ATSDR is committed to evaluating children's special interests at sites such as Fort Devens as part of its Child Health Initiative.
ATSDR identified no situations in which children were or are likely to be exposed to harmful levels of chemical contaminants associated with Fort Devens. ATSDR based its conclusion on the following factors:
- Children have not been exposed, nor are they now or should they be in the future, to harmful levels contaminants when drinking water. Some metals were found in the Ayer Grove Pond wells in the past, but the levels are considerably lower than levels associated with adverse health effects. Children drinking water from public supplies are protected because public suppliers routinely test their water supplies to ensure that it is free of harmful levels of chemicals and that it meets federal and state drinking water standards.
- Children are not likely to have contacted site-related contaminants often or for long periods when using nearby surface water bodies, and are unlikely to do so in the future. Even though some ponds were used for recreation, most located near Fort Devens probably offered limited recreational opportunity for a young child. Today, a precautionary advisory has been posted at the ponds to advise people against swimming in either Grove Pond and Plow Shop Pond. Any infrequent and brief contact to the contaminants that might occur from wading should not pose a hazard for a child.
- Children are not likely to have consumed harmful levels of contaminated fish, nor are they likely to in the future if they observe the fish consumption advisory. Elevated levels of mercury have been detected in some species of Grove Pond, Plow Shop Pond, and Mirror Lake fish. As a precautionary measure, a fish consumption advisory recommends that children not eat freshwater fish from these ponds. By following the advisory, children reduce their exposure to mercury.
Conclusions regarding potential past, current, and future exposures to various environmental media on and in the vicinity of Fort Devens are based on a thorough evaluation of remedial site investigation data, groundwater and surface water monitoring data, municipal drinking water supply data, and observations made during site visits. On the basis of its evaluation, ATSDR reached the following conclusions:
- Elevated levels of VOCs and metals have been detected in groundwater beneath the Fort Devens site. No exposures resulting in public health hazards have occurred or are occurring. The Army will continue to monitor and treat contaminated groundwater to prevent migration to existing water supplies, thereby limiting potential future public health hazards.
- Arsenic, iron, and manganese were detected in Ayer's Grove Pond wells before they were closed in 1993. ATSDR has determined that the concentrations of these compounds are unlikely to cause harmful effects, even for residents who used the water for extended periods. The Ayer Department of Public Works has returned the Grove Pond wells to regular service, but before the water is delivered to residential taps, it is treated for iron, manganese, and arsenic and tested to ensure that the water is safe to drink. The Army, with MADEP and EPA oversight, continues to take precautions and tests groundwater to best protect the underlying aquifers and prevent contamination from reaching the Grove Pond wells.
- Elevated levels of metals were measured in Grove Pond and Plow Shop Pond sediment but were rarely found in surface water. No significant exposure has occurred, is occurring now, nor is expected in the future, however. As a precautionary measure, a "no swimming" advisory has been posted at each pond to advise people against swimming. Any brief and infrequent contact with the ponds' sediment is unlikely to lead to adverse health effects. The Army and EPA are continuing to investigate the contamination at these ponds.
- Some Grove Pond, Plow Shop Pond, and Mirror Lake fish contain elevated levels of mercury. Mercury in fish likely originates from off base sources, including the former tannery. As a precaution, an advisory has been posted to either discourage people from eating fish or to advise them to limit their consumption of fish caught from these water bodies. ATSDR has concluded that by following the precautions, people, particularly young children and pregnant women, can reduce their exposure to mercury.
- ATSDR has determined that air inside the former Devens Elementary School poses no current or future public health hazards from contaminants associated with historic fuel spills. The school was temporarily closed in 1993 (but will reopen in 1999) and the oil-contaminated soil has been removed. Available monitoring data indicates that no harmful levels of contaminants have been found inside the school.
- ATSDR has concluded that the Fort Devens site poses no apparent public health hazard. (A description of this public health hazard conclusion category is included in the glossary.)
The Public Health Action Plan (PHAP) for Fort Devens contains a description of actions taken and those to be taken by ATSDR, the Army, EPA, and MADEP at and in the vicinity of the site after the completion of this public health assessment. The purpose of the PHAP is to ensure that this public health assessment not only identifies public health hazards, but also provides a plan of action designed to mitigate and prevent adverse human health effects resulting from exposure to hazardous substances in the environment. The public health actions that are completed, being implemented, or planned are as follows:
- The Army has investigated more than 81 NPL sites and over 223 BRAC areas requiring further evaluation under CERCLA. Of these, several have been determined to pose no threat to human health or the environment. The Army has completed response actions at many of them. Initial site investigations for NPL sites at Fort Devens were completed by 1996.
- The Army has investigated areas that may have contributed to underlying groundwater contamination and has treated (via soil-vapor extraction) or removed contaminated soil or waste from these areas. The Army has installed wells in many areas of the site to monitor groundwater quality over the long term.
- ATSDR has previously prepared three health consultations that evaluated specific concerns about Fort Devens, including an evaluation of the potential exposure to groundwater contamination at the South Post (1994); an evaluation of potential public health concerns associated with the use of Ayer Grove Pond Drinking Water Wells (1998); and an evaluation of potential public health concerns associated with the recreational use of Grove Pond and Plow Shop Pond (1998).
- MDPH evaluated cancer rates in Ayer for the years 1982 to 1992. Findings from their evaluation showed that the occurrence of cancer in Ayer during that period was approximately equal to or just slightly higher than expected for the majority of cancers.
- The Army has capped the Shepley's Hill Landfill. The Army has conducted groundwater monitoring to determine whether contamination is or could migrate to off-site areas and taken additional measures to ensure the integrity of the cap.
- The Army has studied seven other debris disposal areas, or landfills, located on the property, and found that they have not affected groundwater. Management options for the landfills have been proposed and are under review.
- As precautionary measures, the Army posted a "catch and release fishing only and no swimming" advisory at Grove Pond and Plow Shop Pond, and the MDPH issued a limited fish consumption advisory for Mirror Lake.
- The Ayer Department of Public Works closed the municipal Grove Ponds wells in 1993 following detection of iron, manganese, and arsenic. The ADPW has built a new water treatment system and reopened the wells. Water from the Grove Pond wells, as well as other wells, is regularly tested to ensure that the water is safe to drink.
- Investigations are in various stages at several AOCs and study areas as the Army continues to define the extent of contamination and recommend appropriate remedial actions.
- The Army is conducting long-term groundwater monitoring and maintenance programs associated with Fort Devens, including monitoring near Shepley's Hill Landfill. This system will ensure that the contaminant migration will be carefully tracked and that corrective measures will be taken, if necessary.
- The Ayer Department of Public Works, with EPA oversight, will continue to monitor and treat Grove Pond well water, ensuring that Ayer residents have a clean drinking water supply.
- MADEP has recently completed additional sampling of the surface water and sediment at Grove Pond. Preliminary results indicate that the highest levels of sediment contamination do not appear to be contributing to elevated surface water concentrations (MADEP, 2000). ATSDR will review the final results when they become available.
- EPA, Ayer Department of Public Works, and MassDevelopment have agreed to work cooperatively to replace and maintain signs at key access points (e.g., boat ramps, Pirone Parks, public landings) along Grove Pond and Plow Shop Pond.
- ATSDR has noted that the heating system was inactive during the air monitoring of the Devens Elementary School. ATSDR recommends that if additional sampling is done to 1) ensure that the school is appropriately heated prior to sampling; 2) perform additional VOC sampling without the presence of methylene chloride to ensure that no compounds are of health concern; and 3) collect sufficient grab or time weighted (restrictive orifice) sampling to ensure that methylene chloride is not present.
- ATSDR will review new information on exposure pathways that may be generated from remedial investigation activities.
Federal Facilities Assessment Branch
Division of Health Assessment and Consultation
Amanda Stoddard, M.P.H.
Environmental Health Scientist
Federal Facilities Assessment Branch
Division of Health Assessment and Consultation
Gary Campbell, Ph.D.
Environmental Health Scientist
Federal Facilities Assessment Branch
Division of Health Assessment and Consultation
Technical Assistance provided by:
Brenda Weis, Ph.D.
Federal Facilities Assessment Branch
Division of Health Assessment and Consultation
ABB Environmental Services, Inc. (ABB). 1995. Fort Devens feasibility study for Group 1A sites. Draft Plow Shop Pond and Grove Pond sediment evaluation. Volume I. Sections 1.0-8.0. October 1995.
Agency for Toxic Substances and Disease Registry (ATSDR). 1992. Letters to local boards of health and abutting landowners. RE: Recommendation for "Catch and Release Fishing Only" and "No Swimming" Posting of Plow Shop and Grove Ponds. December 1992.
ATSDR. 1994. Health Consultation: Fort Devens Functional Area 1, Area of Contamination 25, 26, and 27. Ayer, Massachusetts. December 7, 1994.
ATSDR. 1995 Toxicological profile for fuel oils. Atlanta: US Department of Health and Human Services, Public Health Services, Agency for Toxic Substances and Disease Registry. June 1995.
ATSDR. 1998. ATSDR Public Availability Session. Ayer, Massachusetts. March 1998.
ATSDR 1999. Demographics in a 1-mile buffer of the Fort Devens site, based on 1990 U.S. census data. March 1999.
Ayer. 1998. Personal communication with the Ayer town administrator. November 1998.
Ayer Department of Public Works (ADPW). 1998a. Personal communication with Rick Linde, Ayer Department of Public Works. June and July, 1998.
ADPW. 1998b. Meeting at Ayer Department of Public Works with representatives from ATSDR, Environmental Protection Agency, Massachusetts Department of Environmental Protection, and Devens Commerce Commission. October 15, 1998.
ADPW. 2000. Personal communication with Rick Linde, Ayer Department of Public Works. June 14, 2000.
Base Realignment and Closure Environmental Offices (BRAC). 1996a. Cleanup Plan. Fort Devens, Fort Devens, Massachusetts. September 1996.
BRAC. 1996b. Environmental Updates. Spring 1996 to Spring 1998.
BRAC. 1997. Proposed Plan for SAs 6, 12, and 13, and AOCs 9, 11, 40, and 41. U.S. Army Reserve Forces Training Area. Devens, Massachusetts. December 1997.
BRAC. 199X. Proposed plan for defense reutilization marketing office yard (DMRO) (AOC 32) and petroleum, oils, and lubrication storage area (POL) (AOC 43A). Devens, Massachusetts.
BRAC. 1999. Cleanup Plan. Fort Devens, Fort Devens, Massachusetts. September 1999.
Camp Dresser & McKee, Inc. (CDM). 1968. Report on water works improvements HUD project no. P-Mass-3345. March 1968.
CDM. 1993. Town of Ayer, Massachusetts. Grove Pond Wells. Improvement to Grove Pond Wells and pilot treatment study proposal. January 1993.
Devens Commerce Center. 1998. Personal correspondence with Alan Delaney. October 29, 1998.
Ecology and the Environment, Inc. 1994. Remedial investigation report functional area I. Volumes I to V. General Information. Fort Devens, Massachusetts. August 1994.
EPA. 1998. Indoor air sampling study area of contamination 69W Devens Elementary School, Devens, Massachusetts. U.S. Environmental Protection Agency. New England Regional Laboratory. June 1998.
EPA. 1999. Personal communication with Jerry Keefe, EPA Region I. May 11, 1999.
Fort Devens. 1995a. Fort Devens community relations plan for environmental restoration 1995 Update. May 1995.
Fort Devens. 1995b. Record of decision. Shepley's Hill Landfill operable unit areas of contamination 4, 5, & 18. Fort Devens, Massachusetts. September 1995.
Fort Devens. 1996. Record of decision. Areas of contamination 43G and 43J. Fort Devens, Massachusetts. October 1997.
Fort Devens. 1997. Record of decision. Area of contamination 63AX Devens Reserve Forces Training Area. Fort Devens, Massachusetts. October 1997.
Fort Devens. 1999a. Personal communication with Jim Chambers, BRAC Environmental Coordinator. April 30, 1999.
Fort Devens. 1999b. Personal communication with Jim Chambers, BRAC Environmental Coordinator. February 12, 1999.
Haley & Aldrich. 1998. Residential indoor air quality results for Fort Devens base housing, Fort Devens, Massachusetts.
Harvard Water Department. 1998. Personal communication with Jim Smith. June 3, 1998.
Horne Engineering Services, Inc. 1996. Preliminary draft record of decision for the South Post Impact Area Groundwater areas of contamination 25, 26, and 27. February 14, 1996.
Horne Engineering Services, Inc. 1997. Preliminary final record of decision for the defense reutilization and marketing office yard (AOC 32) and petroleum, oil, and lubricants storage area (AOC 43A). Devens, Massachusetts. December 1997.
Lancaster Water Department. 1998. Personal communication with Brad Locke. June 4, 1998.
Massachusetts Department of Environmental Protection (MADEP). 1995. Memorandum from Robert Serbian, MADEP-Westborough to John Regan, MADEP-BWSC. RE: Results for fish samples from Mirror Lake, Fort Devens. September.
MADEP. 1998a. Personal communication with John Regan, Central Regional Office. July 1998.
MADEP. 1998b. Letter from John Regan, Central Regional Office, to Pauline Hamel and Cornielius Sullivan, Ayer Board of Selectman. September 15, 1998.
MADEP. 1998c. Memorandum from John Regan, Massachusetts Department of Environmental Protection. RE: Pesticides at Fort Devens base housing. May 8, 1998.
MADEP. 1999a. Personal communication with John Regan, Central Regional Office. March, 1999.
MADEP. 1999b. Personal communication with Caroline E. Williams, Regional Planner. Central Regional Office. May 7, 1999.
MADEP. 2000. Personal communication with Paul Ollila, Massachusetts Department of Environmental Protection, Central Regional Office. June 19, 2000.
MassDevelopment. 2000. Personal communication with Ron Ostrowski, MassDevelopment, June 16, 2000.
Massachusetts Department of Public Health (MDPH). 1995. Fish consumption advisories for mercury in freshwater fish. Massachusetts Department of Public Health. Presented to the Committee on Health Effects. May 1995.
MDPH. 1997. Letter from Theresa A. Barry, MDPH. RE: Cancer Incidence in Ayer. October 23, 1997.
Nashoba Associated Board of Health. 1999. Personal communication with Walter Murphy, Director. RE: Private wells installed in Ayer, Harvard, Lancaster, and Shirley in 1998.
New England Environmental Technologies Corporation (NEET). 1997. Massachusetts National Guard Maintenance Depot groundwater monitoring data. September 1997.
PACE. 1998. Personal communication from People of Ayer Concerned About the Environment to ATSDR. March 26, 1998.
SEA Consultants, Inc. 1990. Report on water supply and distribution systems study. Ayer, Massachusetts. Department of Public Works, Town of Ayer, Massachusetts. August 1990. U.S. Army Environmental Center (USAEC). 1995. Record of decision. Barnum Road maintenance yards. Fort Devens, Massachusetts. March 1995.
Shacklett, H.T. and Boergen, J.G. 1984. Element concentrations in soil and other surficial materials of the conterminous United States. U.S. Geological Survey profession paper 1270.U.S. Government Printing Office. Washington, DC.
Shirley Water District. 1998. Personal communication with Brian Goodman. June 4, 1998.
TRC Environmental Corporation (TRC). 1999. Summary report for Fort Devens redevelopment-housing decontamination, Devens, Massachusetts.
U.S. Fish and Wildlife Service (U.S. F&W). 1993. Concentrations of mercury and other environmental contaminants in fish from Grove Pond, Ayer Massachusetts. September 1993.
U.S. F&W. 1997. Letter from Kenneth Carr, Acting Supervisor of U.S. Fish & Wildlife New England Field Office, to Dennis Gagne, U.S. Environmental Protection Agency. RE: Review of the draft Plow Shop Pond and Grove Pond sediment evaluation. January 22, 1997. 1993.
Vanasse Hangen Brustlin, Inc. 1994. Devens Reuse Plan. Fort Devens, Massachusetts. November 14, 1994.
1. During the early years of operation, sampling, if any, centered around bacteriological concerns. Later, when the Grove Pond wells were used only for emergencies, sampling probably did not occur because the wells were so infrequently used (MADEP, 1998a).
2. Secondary MCLs are not health-based standards, rather they are unenforceable federal guidelines regarding taste, odor, and color effects of drinking water. EPA recommends them to the states as reasonable goals, but federal law does not require water systems to comply with them.
3. Table 6 summarizes information on contaminants that exceed comparison values only.
4. Though likely not of health concern, it should be noted that detection levels for some of the individual PAHs were slightly higher (up to 0.8 ppm) than ATSDR's comparison value for benzo(a)pyrene.
5. Some samples were "reconstructed" using the fillet and the partial body sample. The concentration for the reconstructed whole body sample is the sum of the fillet concentration and the partial body sample concentration divided by the total body weight.
6. The MDPH, the state agency responsible for issuing fish consumption advisories, uses the FDA action level of 1 mg/kg for mercury in commercial fish as the basis for issuing a full advisory (do not eat any fish). While protective of health, the values do account for economic considerations. MDPH uses 0.5 mg/kg for mercury as the basis for issuing a limited advisory.
7. The Army also conducted two rounds of sampling (1996 and 1997) in the school. Although the tests were qualified as inconclusive because of data quality issues and sample contamination, EPA has used these data to compare to the 1998 EPA testing data.
8. It should be noted that the indoor air samples were taken during the spring when the heating system was inactive. Because the suspected source of contamination has been removed, it is doubtful that any higher concentrations would be present even when the building is tightly closed or in use with the heating system on.