Mid-Atlantic Superfund

EPA Region 3 (Mid-Atlantic)

Maryland
Prince George's County
Brandywine

EPA ID# MD9570024803

2nd Congressional District

Last Update: May 2008

Other Names

None

Current Site Status

The EPA, Maryland Department of the Environmental (MDE), and Prince George County Health Department (PGCHD) and the Air Force signed a Memorandum of Understanding (MOU) on November 23, 2004. The MOU is an agreement to support the Andrews Air Force Base (Andrews AFB) Accelerated Performance-Enhanced Plan (APEP). The APEP envisions having remedies in place at all sites at Andrews AFB and at the Brandywine Defense Reutilization and Marketing Office (DRMO) site by 2009.

EPA, Maryland Department of the Environmental (MDE), and Prince George County Health Department (PGCHD) completed the review of the RI and FS. In addition, the team completed the review of the Engineering Evaluation/Cost Analysis (EE/CA) for the PCB-contaminated soil and sediment removal. A n Interim ROD for groundwater treatment was signed in September 2007. The remedy The investigation did identify that dense non-aqueous phase liquid (DNAPL) was present in the subsurface. However, that portion of the investigation is not complete. A pre-design study to further identify the area with DNAPL contamination in the subsurface will begin in 2007. Total volatile organic compounds (VOCs) detected at concentrations of 240 parts per million while trichloroethylene (TCE) was detected at 224 ppm. The maximum contaminant level (MCL) for drinking water is 5 parts per billion (ppb).

Site Description

The DRMO site is an inactive U.S. Department of Defense (DOD) facility that occupies approximately eight acres of land. The U.S. Navy operated the site as a storage yard and marketing office from an unknown date until 1955, when it was transferred to the U.S. Air Force. In 1973, the Defense Supply Agency (DSA) assumed control of the site, and the Defense Property Disposal Organization (DPDO) received a permit from Andrews Air Force Base (AAFB) to use the property. The Brandywine DRMO site is located in southern Prince George's County, Maryland, about 8 miles south-southeast of AAFB. The site lies within the Potomac River Basin.

From approximately 1953 until 1988, the DRMO site was used principally as a storage area for surplus electrical equipment, other materials, and for storage of hazardous wastes. The site accepted materials, including hazardous wastes, from several installations, including AAFB, Bolling Air Force Base, the Washington Naval Yard, the Navy Research Laboratory, the Naval Surface Warfare Center (NSWC)-Indian Head Ordnance Station, and White Oak Laboratory (now known as NSWC-White Oak). Drums of waste solvents, capacitors and transformers containing polychlorinated biphenyls (PCBs) were stored at the DRMO. Records indicate there were two burn pits used for disposal and burn of waste and several above and below ground tanks. The AF removed the burn pits and tanks in 1989.

Site Responsibility

Cleanup of this site is the responsibility of the federal government.

NPL Listing History

This site was proposed to the National Priorities List of the most serious uncontrolled or abandoned hazardous waste sites requiring long-term cleanup action on July 28, 1999. The site was formally added to the list May 10, 1999, making it eligible for federal cleanup funds.

Threats and Contaminants

Two sources located at the DRMO site were evaluated in the documentation record: soil contaminated with polychlorinated biphenyls (PCBs) and semi-volatile organic compounds in a groundwater contaminant plume. Contamination resulted from the management and disposal of wastes, particularly volatile organic compounds (VOCs), in on site in tanks, drums, warehouses, aboveground storage tanks, underground storage tanks, and burn pits. A transformer storage area was located in the eastern portion of the site. Hazardous wastes were stored directly on the ground.
Observed releases of VOCs to ground water and PCBs to surface water (wetlands) are documented. The surface water migration pathway for the DRMO site includes wetlands located immediately down gradient (to the north and west) from the DRMO property. The surface water flows through a wooded area and eventually joins to form a tributary of Timothy Branch. The Timothy Branch flows south from the Brandywine Area and joins the Mattawoman Creek about three miles south of the site. Wetlands are located along Timothy Branch and Mattawoman Creek for their entire lengths within the 15-mile target distance limit. The State of Maryland has designated Mattawoman Creek and its 100-year flood plain and area of critical concern under the Coastal Zone Management Act; the area is a migratory corridor for anadromous species of fish. The State of Maryland has designated all stretches of Timothy Branch Creek and Mattawoman Creek Class I waters -- that is, waters allowing contact recreation and the propagation of fish and other aquatic life and wildlife. Mattawoman Creek downstream of the site is a fishery.

Contaminant descriptions and associated risk factors are available from the Agency for Toxic Substance Disease Registry (ATSDR), an arm of the CDC, website at:
http://www.atsdr.cdc.gov/hazdat.html

Cleanup Progress

In 1989, the AF initiated and removed polychlorinated biphenyl (PCB) contaminated soil on site. Then in Sept. 1996, the AF issued a Decision Document for the installation of horizontal extraction wells and a treatment system to treat the contaminated groundwater. According to the information provided by AAFB and MDE, at the last minute AAFB changed the design from horizontal wells to an on-site interceptor trench with a treatment system. AAFB explained that the design change was because they did not receive access to off site areas and that private parties wanted compensation. Following the construction of the interceptor trench, AAFB and MDE disputed the issue of permit requirements for the treatment system for almost four years. The treatment system was subsequently turned on. Because the majority of the contamination is off site, the treatment is unable to capture and treat the entire groundwater contaminant plumes.

The remedial investigation and feasibility study (RI/FS) began in October 2001. Sampling activities began in December 2001. There was a Phase 1, a Phase 2, and Phase 2b due to the complex geology and hydrogeological conditions. The Phase 2b effort tried to detect dense non-aqueous phase liquid (DNAPL) in groundwater. The investigation was complete in 2007. It did identify DNAPL of trichloroethylene (TCE). Trichloroethylene (TCE) was detected at 224 parts per million (ppm) or 224,000 parts per billion (ppb) in groundwater. Based upon the detection of DNAPL, an interim ROD was issued to remediate the contaminated groundwater. The selected remedy to treat the contaminated groundwater is Bioagumentation with Gradient Control, Institutional Controls and Groundwater Monitoring. An Engineering Evaluation/Cost Analysis (EE/CA) was finalized in September 2006 for PCB-contaminated soil and sediment removal in the adjacent wetland. The Action Memorandum to fund the EE/CA was signed in 2007. Removal of the PCB-contaminated soil and sediment began in July 2007. The removal is complete as of November 2007. The team is waiting to receive the report documenting that the PCB removal is complete. In addition, a pre-design investigation to further characterize the extent of the DNAPL was completed in 2007. EPA. MDE and PGCHD received the final remedial design/remedial action (RD/RA) work plan for the groundwater treatment in January 2008. The field work for the groundwater treatment began in July 2007 by installing the groundwater interceptor trench on the property purchased by Andrews AFB. 2007. About 50 percent of insitu injections to treat the groundwater are complete. The rest of the injections is expected to be completed later this year. Construction of the groundwater treatment system is complete. Electric hookup expected to be later this summer in 2008.

Contacts

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