PUBLIC HEALTH ASSESSMENT
BRANDYWINE DEFENSE REUTILIZATION AND MARKETING OFFICE
ANDREWS, PRINCE GEORGE'S COUNTY, MARYLAND
Brandywine Defense Reutilization and Marketing Office (DRMO) is a remote facility owned by Andrews Air Force Base (AFB) but operated by the Defense Supply Agency. Prior to 1955, the site was owned and operated by the United States Navy. It is located in Prince George's County, Maryland, about eight miles south of Andrews AFB. The entire 8-acre site is surrounded by a chain link fence and is locked to prevent trespassing.
Prior to 1980, Brandywine DRMO was an active receiving facility for waste solvents and
polychlorinated biphenyl (PCB)-contaminated transformers. It received waste materials from
Andrews AFB, the Navy Research Laboratory, White Oak Laboratory, Bolling AFB, the
Washington Navy Yard, and the Indian Head Naval Ordnance Station. After 1980, Brandywine
DRMO was no longer used as a redistribution and marketing office and no new hazardous wastes
were allowed on site; however, remaining wastes were not completely removed until extensive
removal activities ended in 1994. In May 1999, Brandywine DRMO was placed on the US
Environmental Protection Agency's (EPA's) 
National Priorities List for PCB-contaminated soil and volatile organic compound (VOC)-contaminated groundwater.
- Soil contaminated with PCBs was first investigated in 1986, after spills occurred while transformers were being removed from the site. Since then, three cleanup efforts have taken place to remove all contaminated soil with PCB concentrations above 10 parts per million. The latest removal effort ended in 1994 and involved removing debris, buildings, liquid and solid wastes, storage tanks, and approximately 13,400 cubic yards of soil.
- A plume of contaminated groundwater extends from the northwest corner of Brandywine DRMO into private land. The probable source of the plume includes drums of waste solvents stored on site. In 1996, the Air Force installed a groundwater treatment system to remove VOCs from the groundwater; full-time operation began in August 2000.
ATSDR visited Brandywine DRMO in January 2000 and met with Air Force, EPA, and Prince George's County Health Department personnel. At that time, no immediate public health hazards were identified.
After a thorough review of the available data, ATSDR evaluated four exposure pathways:
Groundwater Pathway. Two off-site plumes have been identified to the northwest of Brandywine DRMO. One is believed to originate to the west of Brandywine DRMO (currently an active railroad track owned by Conrail); the other originates at Brandywine DRMO. Since 1989, groundwater from monitoring wells has been sampled repeatedly and private wells have been identified and sampled. None of the private drinking water wells that were tested contained contaminants at levels of health concern (i.e., the water from these wells is safe to drink). Currently, only one residence in the vicinity of the site still receives drinking water from a shallow groundwater well. Another well on Missouri Avenue has been identified as potentially being in the projected path of the plumes. Currently, neither of these drinking water wells appears to be impacted by the groundwater contamination. All other existing private groundwater wells are not in areas affected by the plumes. To ensure that the water from the wells on Cherry Tree Crossing Road and Missouri Avenue continues to be safe for drinking, ATSDR recommends that the Air Force and/or Prince George's County Health Department periodically sample these wells for VOCs.
Surface Water and Sediment Pathway. Surface water from Brandywine DRMO flows into drainage ditches to the north and west of the site. From there, the water is directed into a wetland area that forms a tributary to Timothy Branch. This wetland flows through a residential area and is easily accessible to children who may play in the creek. However, regardless of the potential use, the levels of contaminants detected in the surface water and sediment were too low to be of health concern.
Soil Pathway. The soil at Brandywine DRMO was contaminated from the storage of PCB-containing transformers at the site. Three remedial actions removed a total of 16,800 cubic yards of PCB-contaminated soil from inside and outside the perimeter fence. Although people are not being exposed to contaminated soil at the site because access was and still is restricted by a fence and a locked gate, children might have been exposed to PCB-contaminated soil if they played in the area outside the fence. After calculating conservative hypothetical exposure doses, ATSDR determined that the detected off-site PCB levels were too low to be of health concern for children who may have played near Brandywine DRMO prior to remediation.
Air Pathway. No information is available about the past burning activities at Brandywine DRMO. Burn pits that contained burnt wood, wire, pipe, and miscellaneous metal were discovered in the northwest portion of the site during excavation activities in 1993 and 1994. Also, in 1987, the main warehouse at Brandywine DRMO caught fire and burned. Data are not available to permit quantitative assessment of these past exposures.
ATSDR evaluated environmental data and exposure information associated with Brandywine DRMO and determined that, overall, the site poses no apparent current public health hazard. No one, including children, is expected to be exposed to contaminated groundwater, surface water and sediment, or soil at unsafe levels. Because the nature and extent of the groundwater plume has not been defined to the north of Brandywine DRMO and because the treatment system has not yet been proven effective in reducing the extent and concentration of VOCs in the groundwater, an indeterminate future public health hazard exists for potential future exposures to contaminated groundwater. Past inhalation of smoke from burning activities may have occurred, but data are not available to fully evaluate this exposure pathway. Therefore, ATSDR considers past exposures to smoke to pose an indeterminate past public health hazard.
Brandywine Defense Reutilization and Marketing Office (DRMO) is an inactive facility on eight acres of land near Brandywine Road and Cherry Tree Crossing Road in Prince George's County, Maryland, approximately eight miles south of Andrews Air Force Base (AFB) [see Figure 1]. The Air Force acquired Brandywine DRMO in 1955 from the United States Navy (Andrews AFB 1999). Prior to remedial activities in 1993 and 1994, the following structures were present on site: two metal framed warehouses, burnt debris from the main warehouse, open concrete storage bins, one concrete loading ramp, three 250-500 gallon above ground storage tanks, three 2,000 gallon underground storage tanks, and several other small structures. Most of these structures have since been removed, leaving only one concrete loading ramp and one small block building enclosed in a perimeter fence. Another small building was built in 1996 to house the groundwater pump and treat system. No one ever lived at Brandywine DRMO.
Residential areas surround Brandywine DRMO to the east, south, and west, with the nearest residence about 100 feet west of the site's boundary (Dames & Moore 1996). The village of Brandywine is about 0.25 mile west of the site and consists of a few small retail businesses. An active railroad track operated by Conrail is to the west, and wooded land is present to the east and north. A light commercial/industrial facility and a petroleum product distributor are to the north. The Army Corps of Engineers is investigating a potential formerly used defense site (FUDS) to the west of Brandywine DRMO.
The principal site contaminants are trichloroethylene (TCE) and tetrachloroethylene (PCE) in the groundwater and polychlorinated biphenyls (PCBs) in the soil. The TCE plume originates in the northwest corner of the site and is probably the result of storing drums of waste solvents on site (IT Corporation 1998b). The PCE plume is thought to originate from the potential FUDS located immediately west of Brandywine DRMO, however, this has not been conclusively established. The PCB contamination resulted from storing PCB-containing transformers on site.
Brandywine DRMO was originally owned and operated as a storage yard for excess materials and wastes by the US Navy. The Air Force acquired it in 1955 and stored bulky aircraft parts, paints, and chemicals at the site (Andrews AFB 1997). Brandywine DRMO also received wastes (some hazardous) from the Navy Research Laboratory, from White Oak Laboratory, from Bolling AFB, from the Washington Navy Yard, and from the Indian Head Naval Ordnance Station. Records indicate that three burn pits were used for disposal of waste. In 1973, operation was transferred to the Defense Supply Agency, but the Air Force retained ownership. Brandywine DRMO was active as a receiving facility for waste solvents in 55-gallon drums and PCB-contaminated transformers in concrete bins until 1980. At that point, Brandywine DRMO was no longer used as a redistribution and marketing office (Halliburton 1995). No new hazardous materials have been stored at Brandywine DRMO since 1980 (Andrews AFB 1999). However, hazardous wastes that were not disposed of or removed remained on site until 1986, when PCB-contaminated transformers were removed and, in 1993, when the remaining 21 drums of liquid or solid waste were removed during remedial actions (Halliburton 1995; PGCHD 1990). Underground storage tanks were also present until 1993 to store heating oil for the buildings on site. Throughout operations, the site has been fenced and locked to prevent trespassing.
Remedial and Regulatory History
The 89th Airlift Wing, located at Andrews AFB, is the agency responsible for remediation at Brandywine DRMO. Under the Department of Defense's Installation Restoration Program (IRP), the 89th Airlift Wing has been conducting environmental investigations and remedial activities since 1985. The Maryland Department of the Environment (MDE) and the Prince George's County Health Department (PGCHD) have provided ongoing oversight and involvement in the IRP process. In May 1999, the US Environmental Protection Agency (EPA) placed Brandywine DRMO on the National Priorities List for soil contaminated with PCBs and for groundwater contaminated with volatile organic compounds (VOCs) [EPA 1999].
In 1985, IRP investigations began at Andrews AFB and its remote facilities to identify potentially hazardous waste sites, to confirm the presence or absence of contamination, to examine potential cleanup alternatives, and to implement the chosen remedies. Brandywine DRMO was one of the original IRP sites identified. In May 1986, four spills occurred during the removal of PCB-contaminated transformers and, in January 1987, a fire destroyed the main warehouse at the south end of the site (PGCHD 1990; Andrews AFB 1999). In 1988, 1989, and 1993, the Air Force excavated PCB-contaminated soil both on-site and off-site and removed PCB-contaminated buildings (Andrews AFB 1998; Halliburton 1995). The groundwater plume is currently being treated by a pump and treat system that was described in the 1998 Decision Document for the Remediation of Brandywine DRMO. The system consists of a groundwater extraction trench, a low profile air stripper that removes chlorinated solvents, and surface discharge of treated groundwater.
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 Air Force officials from the Safety, Public Affairs, Public Health, and Bioenvironmental Engineering Departments; with representatives of the EPA; and with representatives of PGCHD on January 18-21, 2000. ATSDR gathered information regarding potential pathways of human exposure to contaminants. 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 examines demographic information (i.e., 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 about residential history in a particular area--information that helps ATSDR assess time frames of potential human exposure to contaminants. Demographic and land use information for the residential areas surrounding Brandywine DRMO is presented in this section.
Demographics
Brandywine DRMO is located at the intersection of Brandywine Road and Cherry Tree Crossing Road in Prince George's County, Maryland. The Bureau of the Census 1997 population estimates found that 780,541 people resided in Prince George's County. About 56.2% are African-American, 37.6% are white, 4.6% are Asian or Pacific Islander,1.3% are Other, and 0.3% are American Indian. Within Prince George's County are 115 elementary schools, 9 middle schools, 47 secondary schools, 102 private schools, and 3 higher education institutions (Andrews AFB 1999).
In 1994, EPA reported that about 1,200 people lived within a mile of Brandywine DRMO (PRC 1994). About 70.3% are white, 26.3% are African-American, 1.6% are American Indian, 1.3% are Asian or Pacific Islander, and 0.4% are Other. (Andrews AFB 1999).
Land Use
Brandywine DRMO is an inactive site administratively controlled by the Air Force. Access to the site is restricted by a locked gate and a chain link fence. Currently, the only activities planned for the site are groundwater remediation and a Remedial Investigation/Feasibility Study. There are no plans for the Air Force to dispose of this land. In the future, after remediation is complete, the land may be transferred.
Most of the land to the east, south, and west of Brandywine DRMO contains medium and large lots of residential land. The nearest residence is about 100 feet to the west of the site (Andrews AFB 1999). Little agriculture exists in the area because of poorly drained soils. Much of the land that is not residential is forested. A newly constructed light industry/commercial area is located about 850 feet northwest of Brandywine DRMO (Dames & Moore 1998). A commercial petroleum products distributor is located about 350 feet to the north, directly across Cherry Tree Crossing Road. A dog training facility is located adjacent to the eastern border. A fire station is located to the south, across Brandywine Road. An active railroad track, believed to be a potential FUDS, borders Brandywine DRMO to the west. No day care centers or schools are within 200 feet of the site (PRC 1994). The village of Brandywine is located about 0.25 mile west of Brandywine DRMO and contains a few small businesses (Dames & Moore 1998).
Quality Assurance and Quality Control
In preparing this public health assessment, ATSDR reviewed and evaluated information provided in the referenced documents. Documents prepared for the IRP program must meet specific standards for adequate quality assurance and control measures for chain-of-custody procedures, laboratory procedures, and data reporting. The environmental data presented in this public health assessment are from reports produced by the Air Force, MDE, PGCHD, and EPA.The limitations of these data have been identified in the associated reports. After evaluating the data, ATSDR determined that the quality of environmental data available in most site-related documents for Brandywine DRMO is adequate to make public health decisions. Data validation was not available for the PCB-contaminated soil samples collected off site.
EVALUATION OF ENVIRONMENTAL CONTAMINATION AND EXPOSURE PATHWAYS
What is meant by exposure?
ATSDR's public health assessments are exposure, or contact, driven. Chemical contaminants disposed or released into the environment have the potential to cause adverse health effects. However, a release does not always result in exposure. People can only be exposed to a chemical if they come in contact with the chemical. Exposure may occur by breathing, eating, or drinking a substance containing the contaminant or by skin contact with a substance containing the contaminant. Exposure does not always result in harmful effects. The sections below describe the conditions under which harmful effects might be expected to occur. To acquaint readers with terminology used in this report, a glossary is included in Appendix A.
How does ATSDR determine which contaminants and exposure situations to evaluate?
ATSDR scientists evaluate site conditions to determine if people could have been (a past scenario), are (a current scenario), or will be (a future scenario) exposed to site-related contaminants. When evaluating exposure pathways, ATSDR identifies whether exposure to contaminated media (such as soil, water, air, or waste) has occurred, is occurring, or will occur through ingestion, dermal (skin) contact, or inhalation.
If exposure was or is possible, ATSDR scientists then consider how often exposure occurs and whether contamination is present at levels that might affect public health. ATSDR selects contaminants for further evaluation by comparing them against health-based comparison values. Comparison values are developed by ATSDR from scientific literature available on exposure and health effects. These comparison values are derived for each of the different media and reflect the estimated contaminant concentration that is not expected to cause adverse health effects for a given chemical, assuming a standard daily contact rate (e.g., amount of water or soil consumed or air breathed) and body weight.
Comparison values are not thresholds for adverse health effects. ATSDR comparison values establish contaminant concentrations many times lower than levels at which no effects were observed in experimental animals or human epidemiologic studies. If contaminant concentrations are above comparison values, ATSDR further analyzes exposure variables (for example, duration and frequency), the toxicology of the contaminant, other epidemiology studies, and the weight of evidence for health effects.
Some of the comparison values used by ATSDR scientists are described in the glossary in Appendix A and include ATSDR's environmental media evaluation guides (EMEGs), reference dose media guides (RMEGs), cancer risk evaluation guides (CREGs), and EPA's reference doses (RfDs) and maximum contaminant levels (MCLs). MCLs are enforceable drinking water regulations, while CREGs, EMEGs, and RMEGs are non-enforceable, health-based comparison values developed by ATSDR for screening environmental contamination for further evaluation.
More information about the ATSDR evaluation process can be found in ATSDR's Public Health Assessment Guidance Manual at http://www.atsdr.cdc.gov/HAC/HAGM/ or by contacting ATSDR at 1-888-42ATSDR.
If someone is exposed, will they get sick?
Exposure does not always result in harmful health effects. The type and severity of health effects that occur in an individual from contact with a contaminant depend on the exposure concentration (how much), the frequency and/or duration of exposure (how long), the route or pathway of exposure (breathing, eating, drinking, or skin contact), and the multiplicity of exposure (combination of contaminants). Once exposure occurs, characteristics such as age, sex, nutritional status, genetics, life style, and health status of the exposed individual influence how the individual absorbs, distributes, metabolizes, and excretes the contaminant. Together, these factors and characteristics determine the health effects that may occur as a result of exposure to a contaminant in the environment.
There is considerable uncertainty about the true level of exposure to environmental contamination. To account for this uncertainty and to be protective of public health, ATSDR scientists typically use high-end, worst case exposure level estimates as the basis for determining whether adverse health effects are possible. These estimated exposure levels usually are much higher than the levels to which people are actually exposed. If the exposure levels indicate that adverse health effects are possible, then a more detailed review of exposure combined with scientific information from the toxicological and epidemiologic literature about the health effects from exposure to hazardous substances is performed.
Figure 2 provides an overview of ATSDR's exposure evaluation process.
Potential Exposures of Concern at Brandywine DRMO
The issues discussed in this public health assessment were chosen based on evaluations made during the site visits, an examination of environmental data, and concerns raised by the community, the Air Force, and the regulators. This public health assessment discusses those pathways--groundwater, surface water and sediment, soil, and air--that could result in people being exposed to site-related contamination. Table 1 outlines the exposure pathways for Brandywine DRMO. More details about each media are provided in Table 2.
The following sections discuss potential human exposure through exposure to contamination in groundwater, surface water and sediment, soil, and air. The following questions are addressed in this public health assessment:
- Has contaminated groundwater migrated to nearby private drinking water wells? If so, has that contamination resulted in adverse human health effects?
- Have the tributaries of Timothy Branch been contaminated to levels that might be harmful to recreational users?
- Is anyone being exposed to and/or negatively impacted by contaminated soil at Brandywine DRMO?
- Were neighbors exposed to hazardous levels of contamination in the air from past burning activities at Brandywine DRMO?
Each section states the concern, a brief summary of ATSDR's conclusions, and a detailed discussion of the basis for the conclusions. The conclusions are based on the evaluation of data from documents provided by the Air Force, MDE, PGCHD, and EPA. For reference, Appendix A is a glossary of environmental and health terms and Appendix B summarizes the methods and assumptions used when estimating human exposure doses and determining health effects for the identified pathways.
- Pathway: Groundwater
Has contaminated groundwater migrated to nearby private drinking water wells? If so, has that contamination resulted in adverse human health effects?
Conclusion
- Even though there is off-site groundwater contamination originating from the northwest corner of Brandywine DRMO, no one is drinking water with hazardous levels of contaminants. Private drinking water wells in the vicinity of Brandywine DRMO were sampled in 1989 and did not contain chemicals at levels of health concern. One private groundwater well remains in use near the site and another well is potentially within the future path of the plume. The well near the site was sampled by an Andrews AFB contractor and PGCHD in 1997; no contaminants were detected at that time. Neither well appears to be impacted by the contamination at Brandywine DRMO. A treatment system began operation in August 2000 to start to remove VOCs from the groundwater in the vicinity of the site.
Hydrogeology
The water table is shallow, lying approximately two to ten feet below ground surface in the Upland Deposits. A layer of green clayey silts of the Calvert Formation lies below the Upland Deposits at about 25 to 35 feet below ground surface (Dames & Moore 1996). This layer forms an aquitard that allows some water to seep from the Upland Deposits into the lower aquifers (Dames & Moore 1998; IT Corporation 1998b). Below the Calvert Formation are an additional five aquifers, which overlie the basement bedrock (Dames & Moore 1992). The groundwater elevation and flow patterns are monitored by the Air Force on a quarterly basis under the Long-term Monitoring/Operation and Maintenance Program. The groundwater tends to flow northwest away from a local recharge area (IT Corporation 1997a, 1998b); however, variability in rainfall can affect the overall flow pattern (Dames & Moore 1998). For example, a west/southwest flow and a radial flow from the center of the site were described in past monitoring reports (IT Corporation 1997b, 1998a).
Groundwater Use
In the late 1980s, the United States Geological Survey (USGS) identified 12 private wells in the area surrounding Brandywine DRMO--three were located on Cherry Tree Crossing Road, one on Bank Street, four on Brandywine Road, three on Tower Road, and one on Redwood Avenue. Although USGS did not perform a comprehensive survey of the entire Brandywine area, only those wells on Cherry Tree Crossing Road and on Bank Street are of concern because they are in the potential path of the contaminated groundwater. Of the four wells identified on Cherry Tree Crossing Road and Bank Street, three are no longer in service because the residences are now supplied with public water. Until recently, the fourth well was being used to supply drinking water to a resident who could not afford the cost of public water installation. However, the resident is recently deceased and it is uncertain how the well will be used by future occupants. For the purposes of this health assessment, ATSDR still considers this well to be a drinking water source.
Most residences and businesses in the area surrounding Brandywine DRMO were and are still supplied with public water from the Washington Suburban Sanitary Commission; the source of this surface water is the Potomac and Patuxent Rivers. However, public water is not available to all residences (e.g., parts of Missouri Avenue and Brandywine Road, Short Cut Road, and Redwood Avenue). One well on Missouri Avenue has been identified as potentially within the future path of the groundwater plume.
Nature and Extent of Contamination
From 1988 to 1990, USGS installed and sampled 17 monitoring wells on and off site of Brandywine DRMO to determine the nature and extent of groundwater contamination (Gannett Fleming 1997). The water was tested for VOCs, semi-volatile organic compounds (SVOCs), pesticides/PCBs, metals, and inorganics. The Air Force re-sampled the wells in 1991 and performed a remedial investigation that collected an additional 32 groundwater samples to define the groundwater plume (Dames & Moore 1992). The samples were analyzed for VOCs, SVOCs, pesticides/PCBs, and metals. In June 1997, the semiannual groundwater sampling program at Brandywine DRMO was initiated; sixteen wells were sampled and analyzed for VOCs (IT Corporation 1997a). In March 1999, 18 monitoring wells were sampled for VOCs (IT Corporation 1998b).
Seven contaminants were identified in the groundwater: TCE, trans-1,2-dichloroethene (DCE), cis-1,2-DCE, PCE, 1,3-dichlorobenzene (DCB), 1,4-DCB, and methyl ethyl ketone (MEK). TCE has been the primary groundwater contaminant; the highest concentration of TCE [65,000 parts per billion (ppb)] was detected in groundwater from the northwest corner of the site at 25 feet below ground surface (Dames & Moore 1996, 1998). Most of the contamination is located off site and appears to be concentrated below a 20-foot depth (IT Corporation 1997a). The source area for the TCE, DCE, and DCB is located in the northwest corner of Brandywine DRMO (Dames & Moore 1998). Although there are no records of spills, leaks, or onsite burial of wastes at Brandywine (Dames & Moore 1996), the probable source of contamination includes drums of waste solvents which were stored at the site (IT Corporation 1998b). The source of the PCE and MEK has not been identified but is believed to originate to the west of Brandywine DRMO (Dames & Moore 1998).
Even though 26 groundwater monitoring wells have been installed in the vicinity of Brandywine DRMO, the Air Force has not monitored some of these wells because of access issues on private properties (IT Corporation 1998a). As a result, the current and recent groundwater sampling rounds do not include sampling of monitoring wells in the northern extension of the plume. Recent groundwater maps from the Air Force could not define the northern boundary of the TCE plume because of the lack of sampling data. Earlier data show the plume extending further to the north. For this reason, ATSDR does not believe that the extent of contamination has been fully defined in that direction.
MDE sampled one well on Cherry Tree Crossing Road in 1987 and detected TCE at
a level of 10 ppb in this well. In June 1989, USGS sampled 12 private wells
in the vicinity of Brandywine DRMO. Only one well--the same well on Cherry Tree
Crossing Road--contained any contamination (TCE, maximum concentration: 5.3
ppb) at concentrations above EPA's MCL (5.0 ppb). This residence was immediately
provided with bottled water and was hooked up to the public water supply system.
Based on the projected extent of the TCE plume in 1990, a source other than
Brandywine DRMO probably contaminated that well (PGCHD 1990). In 1997, the Air
Force directed a contractor to sample the remaining private well on Cherry Tree
Crossing Road for VOCs. PGCHD performed split sampling with the Air Force at
this well and reported to the homeowner that no VOCs were detected (PGCHD 1998).
The Air Force installed a pump and treat system at Brandywine DRMO in September 1996 to remove VOCs from the groundwater. However, because of permitting issues with the state of Maryland, treatment was not started until February 1999 (IT Corporation 1998b). Following an operations and emissions test, the system was shut down in April 1999 because the effluent failed an evaluation of toxicity for aquatic organisms (IT Corporation 1999). A detailed Toxicity Identification Evaluation/Toxicity Reduction Evaluation was recently completed to determine the cause of the toxicity. According to Andrews AFB personnel, the recommendation from the evaluation is to run the treatment system without any changes. It was determined that the toxicity of the system effluent was attributable to a natural depletion of minerals in the groundwater that proved toxic to aquatic organisms used to surface water conditions. The change in conditions made it difficult for the aquatic organisms to survive in the effluent. The pump and treat system began full-time operation in August 2000.
Evaluation of Potential Public Health Hazard
The level of TCE (10 ppb) found at one private well on Cherry Tree Crossing Road during past sampling was determined to be too low to be of health concern, even when a very conservative exposure scenario (i.e., drinking 2 liters of water a day for 30 years) was considered. Even though the source of the TCE has never been determined, it is believed to be unrelated to Brandywine DRMO. Because the household was supplied with bottled and public water, no further exposures occurred after 1989. No other contamination was detected at levels of health concern at any of the other wells sampled. Appendix B provides further details concerning how ATSDR estimated exposure doses and determined health effects. In addition, according to the 1992 TCE and PCE plume maps, the groundwater contamination did not underlie residences to the north and west of Brandywine DRMO. Therefore, no past public health hazards existed for residents in the vicinity of Brandywine DRMO.
According to the most recent TCE intermediate zone (i.e., 19 to 43 feet below ground surface) groundwater map (March 1999), a concentration of 10 ppb has migrated about 625 feet off site into the residential neighborhood on Bank Street and Cherry Tree Crossing Road. All but one of the residences in this neighborhood are supplied with public water. The one remaining private drinking water well on Cherry Tree Crossing Road is not within the boundaries of the plume; therefore, although TCE is present in the groundwater, no current public health hazards are occurring from drinking water from this well. One well on Missouri Avenue was identified as still being in use. Currently, there is no indication that the groundwater well on Missouri Avenue is being impacted by the groundwater contamination. However, because there is no sampling from this well and the plume's northern boundary has not been defined since 1991, there is no information to demonstrate that the plume has not migrated as far as Missouri Avenue. Therefore, no apparent current public health hazard exists.
An indeterminate future public health hazard exists until the nature and extent of the plumes are more fully defined and the treatment system is shown to be effective in reducing the extent and concentration of VOCs in groundwater. If the pump and treat system fails to control the migration of the plume and the northern boundary remains undefined, the plume could unknowingly migrate to an area where private wells are being used to supply drinking water to residents. The groundwater well on Cherry Tree Crossing Road is of concern due to its proximity to Brandywine DRMO and the one private groundwater well being used on Missouri Avenue is of concern because without effective remediation the plume could potentially migrate that far. To ensure that the water from the wells being used on Cherry Tree Crossing Road and Missouri Avenue remain safe to drink, ATSDR recommends that the Air Force and/or PGCHD sample the well water for VOCs on a regular basis. ATSDR understands that the nature and extent of the plumes will be fully characterized during the scheduled 2001 Remedial Investigation/Feasibility Study.
- Pathway: Surface Water and Sediment
Have the tributaries of Timothy Branch been contaminated to levels that might be harmful to recreational users?
Conclusion
- Children who play in the wetland tributary and recreational users of Timothy Branch are not being exposed to contamination at levels of health concern.
Discussion
Hydrology
Brandywine DRMO is relatively flat, with a slight decline to the northwest (Dames & Moore 1992). When PCB-contaminated soil was removed in 1994, Brandywine DRMO was regraded to drain surface water into perimeter ditches along the northern and western borders (Dames & Moore 1998). The surface water is then directed through culverts located beneath the railroad tracks and Cherry Tree Crossing Road into a wetland area that forms a 0.5-mile long tributary of Timothy Branch (PRC 1994). Timothy Branch flows south for about four miles until it joins Mattawoman Creek. Both Timothy Branch and Mattawoman Creek are designated Class 1 waters by the state of Maryland, a classification that allows recreation and propagation of fish and other wildlife in the waters, but prevents the waters from being sources of drinking water (PRC 1994; EPA 1999).
Nature and Extent of Contamination
In August 1990, USGS sampled surface water and sediment from one of the drainage ditches that receives runoff from Brandywine DRMO (PRC 1994; Gannett Fleming 1997). One pesticide (chlordane, maximum concentration: 0.24 ppb), one PCB (Aroclor-1260, maximum concentration: 5.0 ppb), and one inorganic (lead, maximum concentration: 26 ppb) were detected in surface water samples. One pesticide (4,4-dichlorodiphenyldichloroethane, maximum concentration: 0.0003 ppb) and one PCB (Aroclor-1260, maximum concentration: 0.0099 ppb) were detected in sediment samples. Additionally, surface water from various locations on site was collected and analyzed for pesticides/PCBs, VOCs, SVOCs, lead, and petroleum hydrocarbons in 1993 before PCB removal activities and in 1994 after excavation was completed (Halliburton 1995). Two PCBs (Aroclor-1242, maximum concentration: 1.2 ppb; Aroclor-1260, maximum concentration: 10 ppb), one metal (lead, maximum concentration: 26 ppb), and diesel petroleum hydrocarbons (89 ppb) were detected before excavation. One pesticide (chlordane, maximum concentration: 1.53 ppb) and one metal (lead, maximum concentration: 14 ppb) were detected in a post-excavation sample.
Evaluation of Potential Public Health Hazard
The water from the drainage ditches flows into an off-site wetland area that is easily accessible to children who live in the nearby residential area and may occasionally play in the water or sediment. Because children might be exposed to contaminated media, ATSDR calculated conservative recreational exposure doses for the chemicals detected in the surface water and sediment from all surface water bodies. Appendix B provides further details concerning how ATSDR estimated exposure doses and determined health effects. Based on this evaluation, ATSDR concludes that infrequent exposure to the low levels of contaminants does not pose a health hazard for children who may occasionally play in the wetland tributary or for people who recreate in and along Timothy Branch.
The pump and treat system installed at Brandywine DRMO pumps contaminated groundwater through an air stripper and then releases the treated water to the surface, which eventually drains into the wetland that forms a tributary to Timothy Branch. ATSDR reviewed the effluent sampling performed by the Air Force during an April 1998 test period. None of the VOCs detected in the effluent were at levels of health concern for children (or adults) playing in the wetland or creek downstream from Brandywine DRMO. Only VOCs were sampled because only VOCs were identified as contaminants in the groundwater (Dames & Moore 1998). Based on historical groundwater sampling that analyzed for VOCs, SVOCs, pesticides, PCBs, and metals (Dames & Moore 1992; Department of the Air Force 1989; USGS 1991), ATSDR concurs that only the untreated levels of VOCs pose a potential health concern.
No past, current, or future public health hazards exist for recreational users of Timothy Branch and its tributaries because the chemicals detected in the surface water and sediment were found at levels to low to be of health concern.
- Pathway: Soil
Is anyone being exposed to and/or negatively impacted by contaminated soil at Brandywine DRMO?
Conclusion
- Although extensive PCB contamination existed in the soil at Brandywine DRMO, any public access to the site was and is restricted by a fence and a locked gate. Therefore, exposure to the soil would have been too infrequent and of too short duration to cause adverse health effects. In addition, due to removal efforts, the concentrations of PCBs that are currently present in the soil [below 10 parts per million (ppm)] are not at levels of health concern. Potential past exposure to PCBs in the soil outside the perimeter fence at Brandywine DRMO are also not expected to have caused any adverse health effects.
Discussion
Geology
The top layer of soil in the upland deposits consists of silty sands with clay and gravel. This type of soil extends 25-35 feet below ground surface and contains the water table aquifer. The next layer consists of green clayey silts of the Calvert Formation [Dames & Moore 1998; IT Corporation 1998b].
Nature and Extent of Contamination
Concrete storage bins that were located in the northeast corner of Brandywine DRMO were used to store electrical transformers and capacitors. PCB-contaminated dielectric fluid leaked from the transformers and capacitors and contaminated the soil (Halliburton 1995). In addition, four spills occurred when transformers fell from a truck during a removal effort in May 1986 (PGCHD 1990).
In response to the PCB spills at Brandywine DRMO, over 80 surface and subsurface soil samples were collected by the Air Force, MDE, and PGCHD in 1986 and 1987. The samples were taken both on and off site and were analyzed for PCBs. In addition to PCB analyses, another 90 soil samples were collected and tested for pesticides, VOCs, SVOCs, and metals in 1987 and 1988 (Halliburton 1995). PCBs were found at elevated levels both on and off site. Most on-site concentrations ranged from 25 to 200 ppm. The highest on-site concentration was 2,300 ppm (Halliburton 1995). Concentrations in off-site soil samples ranged from 0.08 ppm to 105,387 ppm, however, the highest concentration was over one hundred times higher than the next highest concentration (855 ppm). Almost half of the off-site soil samples were below the 10 ppm action limit. The highest concentrations were detected adjacent to the fence line and near the northeast corner of Brandywine, where transformers used to be stored. The concentration of PCBs in the soil dropped considerably in samples taken six feet outside the fence line (State of Maryland 1986a, 1986b).
Three PCB-contaminated soil removal actions occurred at Brandywine DRMO. From June to November 1988, the Air Force removed about 300 cubic yards of soil from an area extending two feet within the fence line to three feet outside the perimeter fence (Andrews AFB 1998). The soil was stored on site until July 1989, when it was removed to a hazardous waste landfill in New York (PGCHD 1990). In 1989, an additional 3,100 cubic yards of PCB-contaminated soil were excavated from the northeast corner of the site where the transformers were stored (Andrews AFB 1998). From August 1993 to October 1994, a contractor for the Air Force removed all on-site soil and debris containing a PCB concentration greater than 10 ppm. MDE and the Air Force agreed that 10 ppm was an acceptable PCB concentration for future unrestricted use of the 8 acres of land at Brandywine DRMO. Approximately 13,400 cubic yards of soil were removed during this cleanup operation (Halliburton 1995; Andrews AFB 1998). To prevent contamination from leaving the site during removal activities, erosion and sediment control measures were installed and strict worker safety procedures were followed. The PCB-excavated areas were backfilled with clean soil the same day they were excavated and seeded within seven days (Halliburton 1995).
Evaluation of Potential Public Health Hazard
Brandywine DRMO is and has been fenced and locked to prevent trespassing. It is not expected that anyone would be exposed to contaminated soil on any frequent or regular basis. Additionally, the levels of PCBs that are present (below 10 ppm) are below levels of health concern for both adults and children using conservative exposure assumptions. Appendix B provides further details concerning how ATSDR estimated exposure doses and determined health effects.
Because PCB-contaminated soils were found outside the perimeter fence in 1986, the potential exists for past exposures to have occurred prior to the soil remediation in 1988. However, exposure to contaminated soil would have been infrequent and of short duration. ATSDR calculated conservative exposure doses for PCBs detected in the surface soil outside Brandywine DRMO. Appendix B provides further details concerning how ATSDR estimated exposure doses and determined health effects. Infrequent and incidental exposures to PCBs in the soil are expected to have been too low to cause adverse health effects to anyone who might have occasionally visited the area outside Brandywine DRMO. Therefore, no past, current, or future public health hazards are expected from contact with the soil at Brandywine DRMO or outside the site boundary.
- Pathway: Air
Were neighbors exposed to hazardous levels of contamination in the air from past burning activities at Brandywine DRMO?
Conclusion
- ATSDR cannot evaluate past exposures to smoke from burning activities or the warehouse fire because no data are available for review.
Discussion
Nature and Extent of Contamination
No release of hazardous chemicals to the air has been reported (PRC 1994). However, during excavation activities three areas of burnt debris were identified in the northwest portion of the site. Two areas were shallow and appeared to contain mostly burnt wood. One area was reported to be five feet deep and contained wire, pipe, and miscellaneous metals (Halliburton 1995). In addition, in 1987, Brandywine DRMO's main warehouse caught fire. It is unknown if any hazardous materials were in the warehouse at the time of the fire (Gannet Fleming 1997). No air sampling data are available for review.
Evaluation of Potential Public Health Hazard
Not enough information exists to allow ATSDR to evaluate this pathway fully. Therefore, ATSDR concludes that an indeterminate past public health hazard existed. For more discussion about the warehouse fire, please read the second concern in the next section, Community Health Concerns.
ATSDR identified the following community health concerns through meetings with concerned citizens; contact with the Air Force, PGCHD, and EPA; and review of site documents.
In the late 1980s, community members were concerned that their shallow drinking water wells were contaminated with PCBs, TCE, or other toxic chemicals originating from Brandywine DRMO.
The USGS sampled residential wells in the area surrounding Brandywine DRMO in 1989. Only one private groundwater well had levels of TCE that were elevated above EPA's MCL. Although the source of the TCE in this well is not known, plume maps show that this well was not located within the confines of the TCE plume originating from Brandywine DRMO; therefore, a source other than Brandywine DRMO may have contaminated the well. The household is now supplied with public water and even though the level of TCE was above EPA's MCL, no adverse health effects are expected to result from the exposure. The water from other wells in the area was also tested and was determined to be safe for human consumption. The Groundwater Pathway discussion provides a more detailed explanation.
Community members were concerned about possible exposures occurring during the warehouse fire.
In January 1987, the main warehouse at the south end of Brandywine DRMO caught fire and was destroyed (Andrews AFB 1999). Inhalation exposures that might have occurred during the fire cannot be evaluated because no data are available. However, the circumstances of the fire make it improbable that any adverse health effects would have resulted from breathing the air while the warehouse burned because these exposures would have occurred only once and would have been of short duration. The smoke from the fire probably contained particulate matter and chemicals that were present in the warehouse's structure. These substances could have resulted in acute adverse health effects associated with smoke inhalation for people who were close to the scene of the fire. However, any substances that might have existed would have been dispersed and diluted with clean air. This kind of exposure is not expected to result in adverse health effects to residents living nearby.
Community members were also concerned about possible exposures to airborne contaminants occurring during the cleanup efforts at Brandywine DRMO.
Most of the cleanup actions were completed from August 1993 to October 1994. The Occupational Safety and Health Administration (OSHA) requires strict worker safety during remedial activities. For example, workers cannot be exposed to more than 0.5 milligrams of PCBs per cubic meter of air. For the purpose of determining worker exposure, 32 air samples were collected and analyzed for PCBs during the first five days of remedial actions. No PCBs were detected in any of the air samples (Halliburton 1995). In addition, the workers were required to wear uniforms on top of their personal clothing to prevent contaminants from being transported off site. These uniforms did not leave Brandywine DRMO and were laundered on site. With these kinds of strict safety precautions in place during the cleanup, residents can be assured that their own exposures, if any, were minimal.
One former Brandywine community member inquired about his exposure from playing in the Brandywine DRMO area as a child.
One community member reported to ATSDR that from 1960 to 1972 he played in the woods outside of Brandywine DRMO. To address this concern, ATSDR calculated an exposure dose that represented as specific an exposure as possible (see Appendix B). Based on soil sampling from 1986 and 1987, the man (as a child) was not exposed to harmful levels of PCBs.
Moreover, his exposure was probably significantly lower than doses calculated because of the following factors:
- His exposure dose was calculated based on concentrations detected within six feet of the perimeter fence. PCB concentrations decreased the farther away from the fence the sample was taken. It is not likely that his play activity was restricted to within six feet of the site. Therefore, in reality, he probably contacted a lower level of contamination than what was used to calculate his exposure.
- The dose estimates assume an ingestion rate much higher than that observed in children six years or older (EPA 1997). ATSDR assumes that a child younger than six would probably not have been allowed to play unsupervised in the woods for long periods of time. Therefore, during his play activities, he probably incidentally ingested a much smaller amount of soil than what was used to calculate his exposure.
ATSDR recognizes that infants and children may be more sensitive to environmental exposure than adults in communities faced with contamination of their water, soil, or air. This sensitivity is a result of the following factors: 1) children are more prone to be exposed to certain media (e.g., soil or surface water) because they play outdoors; 2) children are shorter than adults and therefore can breathe dust, soil, and vapors close to the ground; and 3) children are smaller, and therefore childhood exposure results in higher doses of chemical exposure per body weight. Children can sustain permanent damage if these factors lead to toxic exposure during critical growth stages. ATSDR is committed to evaluating children's special interests as part of its Child Health Initiative in evaluating sites such as Brandywine DRMO.
ATSDR did not identify any situations where children were being exposed to harmful levels of contamination at the Brandywine DRMO site. ATSDR based this conclusion on the following factors:
Children are not drinking contaminated groundwater. Most of the houses in the area surrounding Brandywine DRMO are supplied with public water. None of the wells known to be in use (including the ones on Cherry Tree Crossing Road and Missouri Avenue) appear to be impacted by site-related contaminants.
Children may be incidentally exposed to contaminants in the surface water and sediment when they play in the wetland area; however, the levels of chemicals detected in the wetlands were too low to be of health concern for children. The incidental exposure to the chemicals detected would not result in adverse health effects.
Children are not coming in contact with contaminated soil. It is not expected that small children would be able to trespass onto Brandywine DRMO property because access to the site is restricted by a chain link fence. Past exposure to contaminated off-site soils may have occurred prior to remediation in 1988; however, the levels of PCBs detected in the soil were too low to be of health concern for children. In addition, the population expected to be exposed, older children, incidentally ingest a much lower amount of soil than the exposure scenario estimates.
ATSDR has drawn the following conclusions from current environmental data and information concerning the Brandywine DRMO site:
Contaminated groundwater plumes originate from the northwest corner of Brandywine DRMO and migrate off site. In 1989, several private wells in the vicinity of Brandywine DRMO were sampled, and none of the wells contained chemicals at levels of health concern. Currently, only one of these private wells remains in use near the site and another private well is potentially within the future path of the plume. Neither well appears to be located within the plumes. For these reasons, no past or apparent current health hazards exist from groundwater use. An indeterminate future public health exists until the extent of contamination is defined and the treatment system is shown to be effective in reducing the concentration and migration of VOCs in the groundwater.
ATSDR recommends that the Air Force periodically sample the monitoring wells and in cooperation with PGCHD sample the remaining residential wells, in accordance with EPA QA/QC requirements, to ensure that groundwater remains safe to drink. ATSDR concurs with the Air Force's scheduled Remedial Investigation/Feasibility Study to fully define the nature and extent of the plumes and recommends continued monitoring during remedial operations.
Surface water from Brandywine DRMO flows into a wetland system to the northwest of the site and eventually into Timothy Branch. The levels of contamination that were detected are too low to be of health concern. Therefore, no past, current, or future public health hazards exist for recreational users of the wetlands, Timothy Branch, and its tributaries.
Storing PCB-containing transformers contaminated the soil at Brandywine DRMO. By 1994, three remedial actions had removed all PCB-contaminated soil above 10 ppm. Because access to the site is restricted by a locked fence, no current or future public health hazards are expected. Some PCB-contamination was also detected in surface soils outside Brandywine DRMO. Prior to remediation in 1988, past exposures to soils outside the perimeter fence could have occurred. However, the PCB concentrations that people may have been exposed to were expected to be too low to be of health concern. Therefore, no past public health hazard existed either.
An indeterminate past public health hazard existed for people breathing smoke during past burning activities at Brandywine DRMO. Not enough information exists to allow ATSDR to evaluate this pathway fully.
The Public Health Action Plan for Brandywine DRMO contains a description of actions taken and those to be taken by ATSDR, the Air Force, EPA, and PGCHD at and in the vicinity of the site after the completion of this public health assessment. The purpose of the Public Health Action Plan 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, planned, or recommended are as follows:
Actions Completed:
In 1985, the Air Force identified Brandywine DRMO as a potential hazardous waste site as a result of TCE and PCB leaks or spills.
In 1988, the Air Force removed 300 cubic yards of PCB-contaminated soil from two feet within and three feet outside of the perimeter fence.
From 1988 to 1990, USGS installed and sampled groundwater monitoring wells. These wells were re-sampled in 1991, 1997, and 1999 by the Air Force.
In 1989, soil was excavated from the northeast corner of the site where PCB-containing transformers were stored.
In 1989, USGS sampled residential wells in the vicinity of Brandywine DRMO.
From 1993 to 1994, the Air Force removed 21drums of liquid or solid waste, three underground storage tanks, three aboveground storage tanks, various structures, and burnt debris. In addition, petroleum- and PCB-contaminated soil and debris were excavated.
In 1996, the Air Force installed a groundwater treatment system to remediate VOCs. The system was initially started in February 1999, but was shut off in April 1999. In August 2000, the pump and treat system became fully operational.
In August 1997, the Air Force and PGCHD performed split sampling at the remaining private groundwater well on Cherry Tree Crossing Road.
Actions Planned:
PGCHD has requested that a geologic investigation be completed on the Calvert and Nanjemoy Formations to determine if the Aquia Aquifer, an important drinking water source for the southeastern portion of Prince George's County, is protected from TCE contamination.
A Remedial Investigation/Feasibility Study for Brandywine DRMO was approved by the Air Force for 2001. Samples of groundwater, surface water and sediment, soil, and air will be analyzed for VOCs, SVOCs, pesticides, PCBs, and metals. It is ATSDR's understanding that the full extent of the plumes will be defined.
As necessary, ATSDR will review the results from the Remedial Investigation/Feasibility Study when they become available.
Recommendations for Further Action:
As long as drinking water is being supplied from shallow groundwater wells on Cherry Tree Crossing Road and Missouri Avenue, water from those wells should be sampled by the Air Force and/or PGCHD, in accordance with EPA QA/QC requirements, for VOCs on a regular basis to ensure the water remains safe to drink.
ATSDR recommends that the Air Force continue to monitor the extent and rate of migration of the plumes.
A commercial petroleum distribution facility is located to the north of Brandywine DRMO. The company was operating a hydrocarbon recovery system that in 1993 was found to be influencing the TCE plume (SW 1993). MDE directed the company to stop operations of the recovery system in 1993 until further notice. If this recovery system ever begins operating again, ATSDR suggests that TCE be tested for and that appropriate precautions be taken to avoid spreading the TCE contamination further.
Agency for Toxic Substances and Disease Registry (ATSDR). 1998. Toxicological profile for polychlorinated biphenyls. Atlanta: US Department of Health and Human Services. December 1998.
ATSDR. 1999. Toxicological profile for lead. Atlanta: US Department of Health and Human Services. July 1999.
Andrews Air Force Base (Andrews AFB). 1997. Management Action Plan. July 1997.
Andrews AFB. 1998. Comments on EPA Hazard Ranking System Documentation Record, Brandywine DRMO. October 9, 1998.
Andrews AFB. 1999. Draft Community Relations Plan. December 1999.
Dames & Moore, Inc. 1992. Hazardous Waste Remedial Actions Program (HAZWRAP). Report of Findings: TCE Plume Delineation and Source Definition at the Brandywine DRMO Site, Andrews AFB. Bethesda, MD. March 4, 1992.
Dames & Moore, Inc. and HAZWRAP. 1996. U.S. Department of the Air Force. Decision Document for the Remediation of Trichloroethene-contaminated Groundwater at the Brandywine DRMO, Andrews AFB. Bethesda, MD. September 1996.
Dames & Moore, Inc. and HAZWRAP. 1998. U.S. Department of the Air Force. Decision Document for the Remediation of Trichloroethene-contaminated Groundwater at the Brandywine DRMO, Andrews AFB, Revision 1. Bethesda, MD. February 1998.
Department of the Air Force. 1989. Letter to the Section Head of the Solid Waste Programs of the Department of Environmental Resources from Larry Carson concerning sampling on Brandywine DRMO. Andrews AFB. Washington DC. July 7, 1989.
EPA. Exposure factors handbook. Washington, DC. August 1997. Available at URL:
http://www.epa.gov/ncea/exposfac.htm .
EPA. 1999. Brandywine DRMO. October 1999. Available at URL:
http://www.epa.gov/reg3hwmd/super/MD/brandywine/pad.htm .
Gannett Fleming, Inc./Dynamac Corporation. 1997. U.S. Environmental Protection Agency. Data Acquisition Summary Report, Andrews AFB. December 30, 1997.
Halliburton NUS Corporation (Halliburton). 1995. Remedial Action Report: Soil and Tank Removal--Brandywine DRMO. Andrews AFB. Oak Ridge, TN. July 1995.
IT Corporation. 1997a. Air Force Center for Environmental Excellence. Seventh quarterly system evaluation report, long-term monitoring/operation and maintenance program: Sites FT-04, SS-13, ST-17, ST-18, SS-01, Building 1845, ST-19, ST-08, SS-22, Building 5013, and Building 3537. Knoxville, TN. September 1997.
IT Corporation. 1997b. Air Force Center for Environmental Excellence. Eighth quarterly system evaluation report, Sites FT-04, SS-13, ST-17, ST-18, SS-01, Building 1845, LF-06, LF-07, ST-08, SS-22, Building 5013, and Building 3537: Long-term monitoring/operation and maintenance program. Knoxville, TN. November 1997.
IT Corporation. 1998a. Air Force Center for Environmental Excellence. Ninth quarterly system evaluation report: Long-term monitoring/operation and maintenance program, multiple sites. Knoxville, TN. February 1998.
IT Corporation. 1998b. Air Force Center for Environmental Excellence. Quarterly system evaluation report: Long-term monitoring/operation and maintenance program, multiple sites. Knoxville, TN. June 1998.
IT Corporation. 1999. Groundwater Treatment System Operations and Emissions Test, Brandywine DRMO. Knoxville, TN. August 27, 1999.
PRC Environmental Management, Inc (PRC). 1994. Memorandum to Ms. Yazmine Yap-Deffler from Catherine Cooney concerning the Preliminary Ranking Evaluation Activities at Brandywine DRMO. Philadelphia, PA. May 11, 1994.
Prince George's County Health Department (PGCHD). 1990. Memorandum to Main File from Anne Williams concerning remediation status at Brandywine DRMO. Lanham-Seabrook, MD. November 9, 1990.
PGCHD. 1998. Letter to resident from Anne Williams concerning drinking water samples from a house on Cherry Tree Crossing Road. Largo, MD. February 13, 1998.
Southern Well & Recovery Corporation (SW). 1993. Letter to James NG and Ann Williams from Thomas LaMay concerning the Gott Company and Brandywine DRMO. Owings, MD. December 20, 1993.
State of Maryland, Department of Health and Mental Hygiene. 1986a. Memorandum to file from Steve Markowski concerning Brandywine sampling by Fred Wooten (PGCHD), along fence line. October 30, 1986.
State of Maryland, Department of Health and Mental Hygiene. 1986b. Memorandum to file from Steve Markowski concerning Brandywine perimeter sampling (11-13-86) - Lab No. 860938. November 28, 1986.
United States Geological Survey (USGS). 1991. Installation Restoration Program Remedial Investigation/Feasibility Study (RI/FS), Stage 1, Addendum 1. January 1991.
LCDR Danielle DeVoney, Ph.D.
Environmental Health Scientist
Federal Facilities Assessment Branch
Division of Health Assessment and Consultation
Gary Campbell, Ph.D.
Environmental Health Scientist, Section Chief
Federal Facilities Assessment Branch
Division of Health Assessment and Consultation
Table 1. Evaluation of Potential Exposure Pathways at Brandywine DRMO
| Pathway Name | Exposure Pathway Elements | Comments | |||||
| Source of Contamination | Environmental Media | Point of Exposure | Route of Exposure | Exposed Population | Time
of Exposure |
||
| Groundwater | Waste solvents and an unknown source | Groundwater | Drinking water pumped from private groundwater wells | Ingestion Dermal contact Inhalation |
Residents and businesses who use private wells for drinking | Future | Plumes of contaminated groundwater have migrated off site. Residents who are using private groundwater water wells in the area may be exposed to chemicals in their drinking water. |
| Surface water and sediment | Waste solvents and polychlorinated biphenyls (PCB)-containing transformers | Surface water and sediment | Children playing in the wetlands and Timothy Branch | Incidental ingestion Dermal contact |
Children | Past, current, and future | A tributary of Timothy Branch runs near a residential area and might be played in by children. |
| Soil | PCB-containing transformers | Surface soil | Children playing in soil outside the Brandywine fence | Incidental ingestion Dermal contact |
Children | Past
Prior to 1988 |
There is no public access to on-site soil. Prior to PCB-contaminated soil being removed from outside Brandywine DRMO in 1988, children playing near the site may have been exposed to PCBs located in the soil outside the perimeter fence. |
| Air | Burning activities and warehouse fire | Air | Neighbors inhaling smoke during burnings | Inhalation | Residents | Past | No air sampling data is available for review. |
Table 2. Evaluation of Potential Public Health Hazards at
Brandywine DRMO
| Site | Site Description/Waste Disposal History | Investigation Results/Environmental Monitoring Results | Evaluation of Exposure/ Public Health Hazard Category |
Corrective Activities and/or Current Status |
| Brandywine Defense Reutilization and Marketing Office Yard, Spill Site or Storage Area (SS)-01 | This 8-acre remote facility is located about 8 miles southeast of Andrews Air Force Base in Prince George's County. From 1953 to 1961, the US Navy used the site for storage. In 1955, the Air Force acquired Brandywine DRMO and stored excess materials and hazardous wastes at the site. In 1973, operation of Brandywine DRMO was transferred to the Defense Supply Agency, although the Air Force retained ownership. Since 1980 no new hazardous wastes were brought to the site. | Groundwater: Volatile organic compounds (VOCs) [primarily trichloroethylene (TCE)], semi-volatile organic compounds, one pesticide, and inorganics were detected in monitoring wells. TCE was detected in an off-site residential well. | Currently and in the past, no drinking water wells appear
to be affected by the contaminated groundwater. However, the TCE plume is
heading into a residential area where two private groundwater wells could
potentially be impacted in the future.
Public Health Hazard Category: |
Current Installation Restoration Program
Phase: Remedial Action or Response Action
In 1988 and 1989, PCB-contaminated soil was excavated from inside and outside the perimeter fence and from the northeast corner of the site, respectively. From 1993 to 1994, 21drums of liquid or solid waste, three underground storage tanks, three aboveground storage tanks, various structures, and burnt debris were removed. In addition, petroleum- and PCB-contaminated soil and debris were excavated. In 1996, a groundwater treatment system was installed to remediate VOCs. The system began full-time operation in 2000. |
| Surface Water: Two PCBs, two pesticides,
one inorganic, and petroleum hydrocarbons were detected.
Sediment: One PCB and one pesticide were detected. |
The chemicals detected in the surface water and sediment
were at levels too low to be of health concern for children who may play
in Timothy Branch and its tributaries.
Public Health Hazard Category: |
|||
| Surface Soil: Polychlorinated biphenyls (PCBs) and pesticides were detected. In addition, inorganics and dioxin/furans were detected in the burn pits. | Because the site has been fenced and locked, no one contacted
contaminated soils on site prior to remediation. Based on conservative exposure
situations, children who may have played outside of Brandywine DRMO were
not exposed to harmful levels of PCBs.
Public Health Hazard Category: |
Figure 1. Location of Brandywine DRMO
Figure 2. ATSDR's Exposure Evaluation Process
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