PUBLIC HEALTH ASSESSMENT
TOBYHANNA ARMY DEPOT
COOLBAUGH TOWNSHIP, MONROE COUNTY, PENNSYLVANIA
Tobyhanna Army Depot (TYAD) is a communications-electronics (C-E) maintenance and supply depot of the U.S. Army Industrial Operation Command (IOC). The primary mission of TYAD is logistics support for C-E throughout the Army. TYAD covers about 2.2 square miles of Coolbaugh Township, Monroe County which is in the Pocono Mountains of northeastern Pennsylvania. The facility is about 15 miles southeast of Scranton, Pennsylvania.
Past operations at TYAD have resulted in volatile organic compound (VOC) and metals contamination of the groundwater and soil, both on-post and off-post.
As of this printing, TYAD is discussed as three separate operable units and other areas of concern. Operable Unit One consists of waste disposal Areas of Concern(AOC) #4 and #7 (also known as Areas A and B, respectively). Operable Unit Two contains former electrical transformers. Operable Unit Three includes two former hazardous waste facilities. The other areas of concern include the inactive sanitary landfill, the Oakes Swamp disposal area, Barney's Lake/Hummler Run, and the former artillery ranges.
In AOC #4, traces of VOCs were detected in the on-post soil and groundwater. Since 1988, on-post monitoring well testing results have shown that contaminant levels are decreasing with time. AOC #4 poses no apparent health hazard to the public.
In AOC #7, levels of VOCs in the on-post soil and off-post groundwater were first detected in 1981. In 1987, due to the 1986 environmental law revisions, twenty-four residences of Tobyhanna were placed on bottled water. The 24 Tobyhanna residences were connected to the TYAD water supply system in 1991. Buried drums were determined to be the source of soil and groundwater contamination. The drums and drum carcasses were removed in 1995. The concentrations of contaminants in and size of the groundwater plume have been decreasing since 1988. The VOCs detected were not at levels and duration for which possible exposures have resulted in adverse health effects. AOC #7 poses no apparent health hazard to the public.
In Operable Unit Two, the soil immediately around the former electric substation was found to be contaminated with PCBs. In 1994, the contaminated soil and materials were removed from the area. Operable Unit Two poses no apparent health hazard to the public.
In Operable Unit Three, the two former hazardous waste facilities were found to contain traces of hazardous wastes. Decontamination of the structures was completed in 1993 following closure of the Operable Unit Three facilities. Operable Unit Three poses no apparent health hazard to the public.
The inactive landfill had some low levels of VOCs detected in the groundwater. There are no drinking water supply wells near the contaminated groundwater, therefore there is no human exposure to the contaminants. The inactive landfill is no apparent health hazard to the public.
The Oakes Swamp Disposal Area is believed to be contaminated from drums containing paint sludge and other debris. The surface water and sediment has some VOCs and metals present. There is no human exposure to these contaminants, therefore Oakes Swamp is no apparent health hazard to the public.
The fish in Barney's Lake/ Hummler Run had some contaminants detected in the resident and stocked fish. The fish are not used for subsistence, therefore the fish are no apparent health hazard to the public.
The former artillery ranges are located both on- and off-post. The on-post ranges are patrolled and have warning signs posted. The on-post ranges are not a physical hazard. The off-post ranges are located in the Tobyhanna State Park and State Game Lands. These ranges could pose a physical hazard to hunters and the public in areas A and B.
Based on the level of contamination, duration of potential exposure to contaminated environmental media, and the remediation activities conducted at the three Operable Units, TYAD poses no apparent health hazard to the public.
The Agency for Toxic Substances and Disease Registry (ATSDR) was established under the mandate of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) of 1980. (Note: Appendix A provides a listing of abbreviations and acronyms used in this report.) This act, also known as the "Superfund" law, authorized the U.S. Environmental Protection Agency (EPA) to conduct clean-up activities at hazardous waste sites. EPA was directed to compile a list of sites considered hazardous to public health. This list is termed the National Priorities List (NPL). The 1986 Superfund Amendments and Reauthorization Act (SARA) directed ATSDR to perform a public health assessment for each NPL site.
Public health assessments (PHAs) are conducted by scientists from ATSDR (or from states with which ATSDR has cooperative agreements). The purpose of a PHA is to determine whether people have in the past been exposed (in contact with) to or are currently being exposed to hazardous substances and if so, whether that exposure is harmful and should be stopped or reduced. If exposures have occurred, ATSDR uses the PHA to evaluate what actions are required to assist those who may have been harmed.
In conducting the PHA, three types of information are used. A major source of information is the extensive environmental data collected for EPA. This information is examined to determine whether people in the community might be exposed to hazardous substances from the NPL site. If people are being exposed to these contaminants, ATSDR will determine whether the exposure is at levels which might cause harm. A second source of information used in the PHA is community health concerns. ATSDR identifies health concerns of community members and determines whether health problems could be related to exposure to contaminants released from the NPL site. If ATSDR finds that harmful exposures have occurred, health outcome data (statistical medical information) may be used to determine whether illnesses are occurring in the community.
The PHA presents conclusions about whether exposures are occurring, and whether a health threat is present. In some cases, it is possible to determine whether exposures occurred in the past. If it is found that a threat exists, recommendations are made to stop or reduce the threat to public health. ATSDR is an advisory agency. Its recommendations identify actions which EPA, the facility, or local agencies can undertake. If exposures are occurring at levels which could pose a threat to public health, ATSDR can undertake health education activities or certain additional follow-up studies. ATSDR can also identify types of information which might be needed to make public health decisions, if such information is lacking.
ATSDR's public health assessments focus on human exposure to contaminants. Chemical contaminants disposed of or released into the environment at TYAD have the potential to cause adverse health effects; however, a contaminant release does not always result in an exposure. People can only be exposed to a chemical if they come into contact with the chemical. Exposure may occur by breathing, eating, or drinking a substance containing the contaminant or by skin (dermal) contact with a substance containing the contaminant.
This PHA will focus on the drinking water wells contaminated from AOC #7. The groundwater plume and contamination migration extends southeast, therefore the 24 residential wells were contaminated from AOC #7. The pumping of ON-3 could have resulted in the migration of contaminants from AOC #7. The six other on-post drinking water wells were not contaminated because they are upgradient of the contamination.
In preparing this Public Health Assessment, ATSDR relies on the information provided in the referenced documents and contacts. The Agency assumes adequate quality assurance and control measures were followed with regard to chain-of-custody, laboratory procedures, and data reporting. The validity of the analyses and conclusions drawn in this document are determined by the availability and reliability of the referenced information.
In order to evaluate the effect on public health of contaminants at NPL sites, the public health assessment focuses on examining whether people have been exposed to (in contact with) the contaminants. To this end, the two most important tasks in the public health assessment are;
- 1) determining whether people have been exposed to hazardous materials from the NPL facility,
2) if exposure is possible or has occurred, determining whether the exposure is at a level that could be a threat to public health.
When ATSDR conducts a site visit at an NPL site, information is gathered to determine:
- whether contamination exists in the environment,
- whether contamination is in places where people in the surrounding community might
come in contact with the contaminants, and
- if there is exposure, whether there is enough contamination to affect the health of people in the community.
To make these decisions, ATSDR examines ways that people might contact the contaminant, for example, whether the chemical is:
- ingested (eaten or drunk); or
- absorbed through the skin.
Several factors influence the health effects that might result from an exposure to a contaminant. These factors include the concentration of the contaminant, the frequency or duration of exposure, the route or pathway of exposure, and the possibility of exposure to a combination of contaminants. Once exposure takes place, characteristics such as age, sex, nutritional status, genetics, lifestyle, and health status influence how an individual will absorb, distribute, metabolize, and excrete the contaminant. Once these factors have been evaluated, it is possible to decide whether there is truly a completed environmental pathway which could result in a significant public health hazard.
Not all chemicals are a hazard for each of these routes of contact. For example, most metals are not harmful, particularly in very low concentrations, if the only contact is with the skin.
ATSDR personnel visited TYAD on July 8 - 10, 1991, and July 21 - 22, 1992. The purpose of the 1991 visit was to perform the initial site scoping. ATSDR met with representatives of the Army, EPA, and Coolbaugh Township. The visit included a tour of the facility. ATSDR personnel made a follow-up visit in 1992. The purpose of this second visit was to gather data on site contaminants and potential pathways of human exposure.
TYAD is located in Coolbaugh Township, Monroe County, in northeastern Pennsylvania (See Figure One). The facility occupies about 2.2 square miles.
TYAD was initially established as Camp Summerall in 1909 on 33 square miles of land in the Pocono Mountains. The area was used by the Army for machine gun and artillery training. During World War I (WWI) the reservation was used for ambulance and tank training and ordnance storage. Since that time, the facility has been used as a camp for the Civilian Conservation Corps, an artillery training base for West Point cadets, and as a storage and supply area for gliders of the Air Service Command. In 1949, TYAD was purchased from the War Assets Administration by the state of Pennsylvania. In 1951, 2.2 square miles were acquired by the Signal Corps for construction of the depot. The balance of the 33 square miles have remained under the control of the state of Pennsylvania as state game land and parks, including Tobyhanna State Park (ESE, 1991a). The vicinity of TYAD and Tobyhanna State Park is predominantly rural agricultural land. Currently, TYAD is a communications-electronics (C-E) maintenance and supply depot of the U.S. Army Industrial Operation Command (IOC).
After discovering volatile organic compounds (VOCs) in residential drinking water wells, TYAD was placed on the National Priorities List (NPL) on August 30, 1990. The U.S. Army and EPA entered into a Federal Facilities Agreement (FFA) effective January 19, 1991 (PRAP, 1995, p. 3). The remedial investigation, to identify the source and location of contamination and the remediation measures needed, was conducted under the terms of this agreement.
ATSDR examines the demographics of communities that are near NPL sites for many reasons. The local demographics may be useful in identifying the presence of sensitive subpopulations, such as young children or the elderly, or in providing information on the length of residency and, therefore, the length of potential exposure to contaminants. The demographics of Coolbaugh Township are examined because of its proximity to TYAD and to assist in the evaluation of community health concerns.
TYAD is in Coolbaugh Township, which is a sparsely populated part of Monroe County, Pennsylvania. The population of Monroe County is approximately 79,317 (ESE, 1990, p.2-1). Only 6,756 people live in the 86 square mile area of Coolbaugh Township (79 persons per square mile). Population and housing data for Coolbaugh Township are found in Tables 1 and 2.
The population of the township is almost entirely white, and less than 6% of all persons are of Hispanic origin. The percentages of the population under age 10 (17.2%) and age 65 and older (13.0%) are considered to be average.
Over 77% of all households are owner-occupied. That is a very high percentage and suggests that the area has a stable, or nontransient, population since renters move much more frequently than do homeowners. Less than 1% of the population lives in group quarters, and there is likewise a low percentage of mobile homes in the township. The median value of owner-occupied housing units and median rent are both consistent with other townships in the area. These statistics are indicators of socioeconomic status and are consistent with other townships in the area.
ATSDR evaluated environmental data, such as soil, groundwater, and air, from the remedial investigation reports. It was determined that the soil in OU-1 and OU-2 and groundwater of AOC #7 are the only media which could result in exposure and a possible threat to human health. Therefore, the soil and groundwater are discussed in this document, in addition to some areas of local concern which do not pose a threat to human health.
Operable Unit Two consists of electric transformers, which contaminated the soil with polychlorinated biphenyls (PCBs; see Figure Two). In August 1989, 26 soil samples were taken around the transformers at depths of 0 to 6 inches below ground surface. All of the PCB levels detected were below 2.7 mg/kg, except for three samples, which had levels of 5,300 mg/kg, 9.9 mg/kg, and 6.1 mg/kg (ERM, 1995, p. 2-13). ATSDR's Environmental Media Evaluation Guide (EMEG) for adult soil exposure is 10 mg/kg. Additional samples were collected using soil borings at depths of 1, 2, and 4 feet below ground surface. Only one soil boring sample detected PCBs at 0.16 mg/kg.
The area around the transformers is used exclusively for commercial purposes. Past site-specific information on exposure to PCBs and duration of exposure is not available. It is probable, however, that previous incidental human exposure would have been limited to workers and would have been of short duration.
All equipment, structural materials, and contaminated soils and concrete have been removed as part of a time-critical removal action completed on September 6, 1994 (ERM, 1995, p. 4-42). The ROD was signed in September 1996. ATSDR concludes that Operable Unit Two does not pose a present or future threat to human health.
Operable Unit Three consists of two former RCRA hazardous waste storage facilities, Building 10-C and Building S-90 (see Figure Two). In January 1993, these buildings ceased to house hazardous wastes when Building H-56 was built under a Pennsylvania Department of Environmental Protection (PADEP) RCRA Part B Permit (PRAP, 1995). In accordance with Pennsylvania closure procedures, the following activities were performed: (1) removing hazardous wastes from buildings; (2) inspecting building interiors; (3) vacuuming walls and floors; (4) decontaminating buildings; (5) sampling building interiors and exteriors; (6) performing a risk assessment; and (7) certifying closure in accordance with the RCRA Part B Permit (PRAP, 1995).
Air, wipe, concrete, and interior soil sampling was performed on buildings S-90 and 10-C from April 12 to May 19, 1993, to determine the contaminants present (USAEHA, 1993). Tables F-6 and F-7 in USAEHA, 1993, provide a complete list of contaminants detected in buildings S-90 and 10-C. Twenty-three air samples were collected from both buildings. The contaminants detected were not above the background levels.
Twenty-two and twenty-one wipe samples were collected from building S-90 and building 10-C, respectively. There were no detections of PCBs in Building S-90. Cyanide was detected once at 2.4 ug/100 cm2. Since cyanide was only detected once, it is not of public health concern. PCBs (Aroclor 1260) were detected in Building 10-C at 1.76 ug/100 cm2 and 12.60 ug/100 cm2 (USAEHA, 1993). The PCBs were only detected twice in wipe samples, furthermore the human exposure pathway would be through incidental contact with surfaces. It is not likely that ingestion of contaminants would result from the incidental contact and that those contaminants ingested would result in adverse health effects. The PCB contamination is not of public health concern.
Fifteen and ten concrete samples were collected from buildings S-90 and 10-C, respectively. VOCs and metals were detected in the concrete. The VOCs were determined to result from the epoxy coating, not from spills or contamination (USAEHA, 1993). The metals were determined to be natural components of concrete because they were detected in the majority of the samples and in background samples.
Thirteen interior soil samples were taken from building S-90. No contaminants were detected in the samples (USAEHA, 1993).
Forty-one exterior soil samples were taken around buildings S-90 and 10-C at ground surface, 1-2 feet, and 2-3 feet. The surface soils were of greatest concern because of the potential human exposure pathway. Thirteen SVOCs were detected, but were not at a level of public health concern. These SVOCs could be present due to vehicle traffic, emissions from the coal fired heating plant, asphalt paving, and the moving and storage of outdoor equipment. These SVOCs are listed in Table F-10, USAEHA, 1993. Nickel was detected in all of the samples, ranging from 7.3 mg/kg to 31 mg/kg. The adult RMEG for nickel is 10,000 mg/kg, therefore the nickel detections are not of public health concern.
The sampling information collected during closure of OU-3 (buildings S-90 and 10-C) was used to carry out a risk assessment. The risk assessment included carcinogenic and non-carcinogenic risks (see USAEHA, 1993, p. F-10 and F-12). The exposures evaluated were for workers with an 8-hour maximum workday. The exposures included indoor air inhalation, dermal contact with interior dust, ingestion of interior dust, ingestion of exterior surface soil, and dermal contact with exterior surface soil (USAEHA, 1993, p. 68). These exposures were summed to determined the carcinogenic and non-carcinogenic risks. The estimated carcinogenic risk for OU-3 is 1 x 10-5 (one in one hundred thousand). The EPA has established an acceptable range of 1 x 10-4 to 1 x 10-6 for carcinogenic risks. The estimated non-carcinogenic risks (Hazard Index) for Buildings 10-C and S-90 are 0.08 and 0.05, respectively (PRAP, 1995). A Hazard Index greater than 1.0 could indicate the potential for non-carcinogenic effects to occur from exposure to contaminants. These risk levels are not of public health concern.
After a December 10, 1993, site inspection, PADEP decided that OU-3 had met the qualifications of the closure plan (PRAP, 1995). The ROD was signed in June 1996. Buildings 10-C and S-90 will be used to store non-hazardous materials. The anticipated future use of OU-3 is only by commercial workers, no residential use is expected (PRAP, 1995). Based on the sampling information, the estimated carcinogenic and non-carcinogenic risks, and the removal of contamination, ATSDR concludes OU-3 is no apparent public health hazard.
There are seven on-post water supply wells (see Figure Three). No contaminants were detected in the drinking water wells ON-1, ON-2, ON-4, ON-5, and ON-6 (ESE, 1991a). Well ON-7 is not used as a source of drinking water, but rather to provide water to a fish rearing tank (ERM, 1997). These water supply wells are not in the groundwater plume path and are far removed from the source of groundwater contamination. It is not likely that any exposure to contaminants will result from these on-post drinking water wells because they are upgradient from the groundwater contamination. The water supply wells ON-1, ON-2, ON-4, ON-5, ON-6, and ON-7 are not of public health concern. Contaminants were only detected in well ON-3, but the water is treated with an air stripper to remove VOCs.
AOC #4(see Figure Two)
In AOC #4 contamination was detected primarily in monitoring wells (MW) 01 and MW02. The contaminants of concern were VOCs (i.e., trichloroethylene (TCE), tetrachloroethylene (PCE), 1,2-dichloroethene, and vinyl chloride) and inorganic compounds (i.e., lead and mercury) (ESE, 1991b, p. 2-52). The contamination is assumed to come from waste disposal and burning. There are no records indicating the type and quantity of disposed wastes (ESE, 1991c, p.1-19). The area affected by contaminants from AOC #4 has been delineated by monitoring wells and did not affect any on- or off-post drinking water wells. Because there is no exposure to the population, the groundwater contaminants detected in monitoring wells will not pose any threat to human health. It is recommended that there will be no remediation, other than natural attenuation, of the groundwater or soil in AOC #4 (TYAD, 1996).
AOC #7 (see Figure Two)
Soil contamination of AOC #7 was first detected in 1987 through soil gas sampling. AOC #7 is located in the southern end of the installation, outside the gated perimeter of the main warehouse, but within the entire base perimeter, in an industrial area. Specifically, AOC #7 is a small clearing in a wooded area adjacent to a large gravel parking lot used for the storage of materials for roads and grounds maintenance (OHM, 1995, p. 1-1).
A work plan for excavation of the contaminated soil was submitted to the U.S. Army Corps of Engineers (USACE) on June 28, 1995, by OHM Remediation Services Corp (OHM). Remediation began on July 10, 1995. At that time, six drums and four or five drum carcasses were located and removed from the site. These drums were determined to be the source of contamination. In January 1996, the contaminated soil was transported and disposed of in the Empire Landfill, Taylor, Pennsylvania (OHM, 1996). A total of 2,089 cubic yards of soil was removed from the area, reducing the levels of TCE and PCE to 1.677 mg/kg and 4.66 mg/kg, respectively. These levels were the established risk-based action levels. After excavation was complete, the area was backfilled with clean fill, covered with topsoil, and planted with grass seed.
The drums and contaminated soil in AOC #7 were the source of the groundwater plume affecting the on-post well number three and off-post drinking water wells. The groundwater plume is naturally attenuating and will eventually dissipate since the source of groundwater contamination has been removed. The groundwater contamination of AOC #7 will be discussed later in this document.
ATSDR concludes that the soil in AOC #7 does not and will not pose any threat to human health. The AOC #7 soil is assigned a classification of no apparent health hazard.