PUBLIC HEALTH ASSESSMENT
TOBYHANNA ARMY DEPOT
COOLBAUGH TOWNSHIP, MONROE COUNTY, PENNSYLVANIA
The community health concerns evaluated in this section represent concerns expressed about potential pathways of human exposure. ATSDR obtained information from proposed work plans, remedial investigation reports, sampling data, site visits, public meetings, and newspapers.
- What are the possible health effects from using on-post and off-post drinking water wells contaminated by VOCs?
- Health effects are not likely to occur from past use of the contaminated on-post and off-post
drinking water wells. The VOCs detected were not at levels or duration of exposure
sufficient to result in adverse human health effects. Current or future adverse health
effects are not likely to occur because the source of groundwater contamination has been
removed. Contaminants have not been detected in the current drinking water supply wells
at levels which could result in adverse human health effects. The drinking water is no apparent health hazard.
People can be exposed to contaminated groundwater from either private wells or public water supply wells by drinking it, bathing in it, or breathing vapors in steam (for instance, in a hot shower).
In 1981, an Initial Installation Assessment (IIA) detected VOCs in on-post and off-post drinking water wells. At that time, the Maximum Contaminant Levels (MCLs) for TCE and PCE were 45 ppb. In 1986, the MCLs were lowered to 5 ppb (TYAD 1996). The U.S. Army Toxic and Hazardous Materials Agency (USATHAMA) Installation Restoration Division then determined that facilities, such as TYAD, with contaminants above 5 ppb had to be reevaluated (ESE, 1988, p. 1-1).
The AOC #7 groundwater sampling data from August 8, 1988, to October 25, 1990, show elevated levels of VOCs (TCE and PCE) in the on-post drinking water well ON-3 and the 24 private drinking water wells off-post in Tobyhanna, all drilled into the Bedrock Aquifer (ESE, 1991d; TYAD, 1996; see Figure Four).
In 1989, a maximum of 13.3 ppb TCE and no PCE were detected in TYAD water supply well ON-3 (ESE, 1991a, p. 5-16). Since 1989, water from ON-3 undergoes air stripping, to eliminate any VOCs present. After the MCL for TCE was reduced to 5 ppb in 1986, well ON-3 was not used until the air stripping device was installed and reduced TCE levels below 5 ppb. The levels of TCE in well ON-3 have been below 3 ppb since 1993 (TYAD, 1996). The levels of TCE are not sufficient to result in any adverse human health effects.
Sampling of nearby Tobyhanna residential wells (see Figure Four) in 1988 found a maximum value of 40.2 ppb TCE and 12.0 ppb PCE (ESE, 1991a, p. 5-28; see Table Three). The 24 residences of Tobyhanna with contaminated drinking water wells were placed on bottled water in 1987, until connection to the TYAD on-post potable drinking water system was constructed in June 1991(ESE, 1991c, p. 1-16). The TYAD drinking water supply system draws water from wells ON-1 through ON-6. Well ON-3 undergoes air stripping to remove any VOCs which may be present. The entire TYAD drinking water supply system is monitored regularly to assure safe drinking water.
Data from on-post monitoring wells was used to determine the direction of groundwater flow and contamination migration in the Bedrock Aquifer. The groundwater in the Bedrock Aquifer in AOC #7 flows 62.3 ft/yr to the south-southeast (ESE, 1991c).
The duration of exposure to contaminants in the drinking water wells can only be estimated. The source of contamination was determined to be waste disposed of in AOC #7 of OU-1. In order to evaluate the potential for adverse health effects from use of this water, ATSDR assumed that the drums in AOC #7 were buried in 1950 and contamination of the drinking water started immediately. The new water supply system was connected in 1991, resulting in a maximum duration of exposure of 41 years. ATSDR then assumed exposure to contaminants by bathing, breathing vapors from steam, and rinsing food, in addition to ingestion of drinking water. ATSDR doubled the maximum concentration of VOCs detected in the groundwater, 40.2 ppb TCE and 12.0 ppb PCE, to account for the total exposure pathways. The total exposure from this assumed "maximum exposure scenario" was still determined not to be a public health concern. The cancer risk was calculated to be 1.58 x 10-5 for TCE and 2.2 x 10-5 for PCE. The contamination sources, drums and drum fragments, were removed in 1995, thereby, eliminating any future contamination (TYAD, 1996).
The Post Remedial Action Plan proposed a pump and treat method for removing contaminants from the groundwater. This plan has since been abandoned due to the decreased groundwater plume size and decreasing concentration of contaminants (TYAD, 1996). The remainder of the plume will be monitored regularly and allowed to naturally attenuate.
The TYAD water supply system and Tobyhanna residential drinking water wells will continue to be monitored for potential contamination. The 24 residences with contaminated groundwater which were placed on the TYAD water supply system will not experience future contamination because the TYAD water supply wells are upgradient from the contamination source. The balance of the Tobyhanna residential drinking water wells are not likely to experience contamination because those wells are further from the contamination source and the groundwater plume is decreasing in size and concentration. Therefore, the residents of Tobyhanna do not have any current or future threats to human health due to groundwater contamination.
- Is AOC# 1, Inactive Sanitary Landfill (see Figure Two), a public health hazard?
- Contaminants from the inactive sanitary landfill migrated into the groundwater. There are
no drinking water supply wells around the landfill or down gradient from it. There is no
human exposure to the contaminants, therefore there is no health hazard.
The landfill operated from 1963 to 1979 receiving all types of waste, such as plating wastes, sludge from the sewage treatment plant, ash from burning of wooden and paper waste, construction debris, paints, solvents, oils, and sanitary solid waste (ERM, 1995).
The contaminants from the landfill have migrated into the groundwater underneath the inactive landfill. Benzene, 1,2-dichloropropane, methylene chloride, PCE, and vinyl chloride were detected above the MCLs in the monitoring wells (ERM, 1997). There were no VOCs detected in the surface water or sediment. The groundwater flows south-southwest. Based upon the data available to ATSDR, there are no drinking water supply wells around the landfill or down gradient. There is no exposure to the contaminants, therefore there is no public health hazard. Additional off-post monitoring wells should be installed to evaluate the potential migration of contaminants.
- Is AOC# 8, Oakes Swamp Disposal Area (see Figure Two), a public health hazard?
- Based upon the available data to ATSDR, the Oakes Swamp Disposal Area does not have a
human exposure pathway, therefore it does not pose a threat to human health.
The Oakes Swamp Disposal Area is on a hillside north of Perimeter Road overlooking Oakes Swamp. The specific disposal practices that may have occurred here are unknown, but drums believed to contain paint sludge and other debris are presumed to be the source of contamination (ERM, 1995).
Sampling was performed on the surface water and sediment in 1992 and 1993 (ERM, 1995). There were some VOCs and metals detected in the surface water. No VOCs were detected in the sediment. Metals were detected only in the surface layers of the sediment. Metals were not detected in sediment samples taken at a depth of two feet. The rusted drums and other debris found in the swamp are assumed to be the source of contamination. Scrap and remanents of drums, car frames, and sheet metal were removed from the banks of Oakes Swamp (TYAD, 1996). The data available to ATSDR at this time indicate there is no human exposure to these contaminants, therefore they do not pose a public health hazard. The installation is scheduled to release a document summarizing the remediation process at the Oakes Swamp in 1997.
- Is AOC# 61, Barney's Lake/Hummler Run (see Figure Two), a public health hazard?
- Based upon the data and information available to ATSDR, the fish in Barney's Lake/
Hummler Run do not pose a public health hazard. The fish are not used for subsistence,
therefore the contaminants detected will not result in a exposure which could cause a public health hazard.
Barney's Lake is stocked with Brown Trout three or four times during the months of April to October. Anyone can fish from Barney's Lake/ Hummler Run during the stocking months, but only TYAD personnel can fish during the remainder of the year. When the lake is stocked, there is a peak in fishing and the stocked fish are largely fished-out within a few weeks. The fish in Barney's Lake/ Hummler Run are not used for subsistence (TYAD, 1996).
In October 1994, fish samples were collected from Barney's Lake and Hummler Run. The samples were tested as fillet data, the remaining carcass, and whole body samples. ATSDR assumed that most people would only eat the fillet and therefore focused on the fillet samples. The reference sites were White Deer Lake and the West Fork of the Lehigh River, both about 15-20 miles from the site. Barney's Lake and Hummler Run were stocked the day before sampling took place. Therefore, some fish had been in the waters for some time and others were new (ERM, 1996). PCBs, arsenic, dieldrin, and manganese were some of the contaminants detected in the fish samples. PCBs were detected at a maximum of 0.31 ppm in Barney's Lake and 0.49 ppm in Hummler Run fish samples, these samples were above the EPA Region III Risk-Based Concentration of 0.095 ppm. Arsenic was detected at a maximum value of 0.6 ppm in fish from Barney's Lake, which was above the Risk-Based Concentration of 0.41 ppm. No arsenic was detected in Hummler Run fish samples. Dieldrin was detected at a maximum value of 0.0017 ppm in Barney's Lake and 0.1 ppm in Hummler Run fish samples. The comparison value for Dieldrin was 0.0002 ppm. Manganese was detected at a maximum value of 9.06 ppm in Barney's Lake and 1.03 ppm in Hummler Run fish samples. The comparison value for manganese was 6.8 ppm. The Risk-Based Concentrations are based on the assumption that a person is consuming an average of 1.89 ounces of fish per day.
Although some contaminants were detected in the resident fish and stocked fish, the contaminants were not at levels of public health concern unless the fish were used for subsistence. Based on the data available to ATSDR, the fish in Barney's Lake/ Hummler Run do not pose a public health hazard.
- Are the Former Artillery Ranges a physical hazard (see Figure Five)?
- ATSDR reviewed the procedures used to determine the presence of Unexploded Ordnance
(UXO) on and off site and the process used to eliminate exposure. The on-post precautions
are protective of public health and safety. The off-post ordnance may pose a physical
hazard to hunters and the public in areas A and B.
The on-post former UXO range is fenced and has warning signs posted. This is a restricted area, therefore there is no human exposure to the source of physical hazard. The on-post former UXO range does not pose a physical hazard (TYAD, 1996).
Based on the historical documents reviewed and site investigations performed on April 6-14, 1995 and July 10-14, 1995, there are three off-post former artillery ranges, areas A, B, and C, of public concern (USACE, 1995, p.5). When live rounds were discovered, the 54th Explosive Ordnance Disposal Det. at Fort Monmouth, New Jersey, was notified and the rounds were destroyed the next day (USACE, 1995, p.5).
Area A is northeast of TYAD in the Tobyhanna State Park. Live 75MM/3" and 155MM rounds have been found at area A. Area A is of public concern because it is in the unrestricted Tobyhanna State Park. An Engineering Evaluation/Cost Analysis has been recommended for this area by the USACE.
Areas B and C are southwest of TYAD in the Game Lands Parcel (USACE, 1995). Areas B and C are of public concern because during hunting season, the public has unrestricted access to these areas. An Engineering Evaluation/Cost Analysis has been recommended for area B by the USACE. Area C is considered to be only a potential ordnance area because no ordnance has been confirmed, an extended site investigation (ESI) was recommended by the USACE. Since the ESI was not approved, an EE/CA was recommended for area C (Rock Island, 1996).
Warning signs are posted throughout the State Park and Game Lands (TYAD, 1996). The off-post former artillery ranges may pose a physical hazard to the few hunters and hikers walking around area A or B.