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Memphis Defense Depot
National Information
Photos/Multimedia
Site photo goes here.
- Additional Site Photos
- Site Video
Additional Resources
- Site Cleanup Terms - can be found in EPA's glossary
- EPA Guides to Cleanup Technologies
- Superfund Community Involvement (PDF) (17 pp, 130K, About PDF)
Site Summary Profile
EPA ID: TN4210020570Location: Memphis, Shelby County, TN
Lat/Long: 35.093330, -090.003330
Congressional District: 23
NPL Status: Proposed: 02/07/92; Final: 10/14/92
Affected Media: Ground water, Sediment, Soil, Surface water
Cleanup Status: Physical cleanup activities have started
Site Reuse/Redevelopment: Portions of site in reuse / planned or actual reuses include residential, industrial, public, and recreational uses
Site Manager: Turpin Ballard (ballard.turpin@epa.gov)
Site Background
The Memphis Defense Depot (Depot) comprises 642 acres in a mixed residential/commercial/industrial area of south-central Memphis. The Depot includes two adjacent sections:
- Main Installation - approximately 578 acres with open storage areas, warehouses, former military family housing, and outdoor recreational areas.
- Dunn Field - approximately 60 acres with an open storage and burial area.
The area surrounding the Depot contains small commercial and manufacturing uses to the north and east and single-family residences to the south and west.
The Depot started operations in 1942, providing material support including clothing, food, medical supplies, electronic equipment, petroleum products, and industrial chemicals to all U.S. military services. During operations, the Depot conducted numerous operations utilizing hazardous substances with contamination resulting from leakage, spillage, disposal of out-of-date materials, and normal application of pesticides. In 1946, the Army disposed of leaking mustard bombs (chemical warfare agent) at Dunn Field. Among the wastes disposed of at the Depot were oil, grease, paint thinners, methyl bromide, pesticides and cleaning fluids (chlorinated solvents).
In 1995, the Depot was placed on the list of the Department of Defense (DOD) facilities to be closed under the Base Realignment and Closure (BRAC) process. Storage and distribution of material continued until the facility closed in September 1997. The Depot Redevelopment Corporation (DRC) is planning and coordinating the reuse of the Depot. Since October 1997, DRC has completed 27 subleases accounting for the reuse of more than four million square feet of covered and uncovered facilities (94 percent of the Main Installation) and the production of approximately 982 jobs. All of the Depot property is to be transferred for reuse. Actual or planned reuses include housing, a golf course, a police precinct, and the DRC Memphis Depot Business Park.
Environmental assessment activities at the Depot began in the 1980s. The Depot was placed on the final National Priorities List in 1992. The lead agency for the environmental restoration activities at the Depot is the Defense Logistics Agency (DLA), with oversight provided by EPA and the Tennessee Department of Environmental Conservation (TDEC).
Threats and Contaminants
Contaminants have been identified in ground water, sediment, soil, and surface water. Examples of contaminants of concern for the site include arsenic, dieldrin, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, tetrachloroethene, and trichloroethene.
Site Cleanup Plan
Environmental restoration activities at the Depot, including the identification, investigation, and cleanup of contaminated sites, have been undertaken under both the federal Resource Conservation and Recovery Act (RCRA) and Superfund law. Since early 2005, all corrective action activities have continued under Superfund authority.
To assist Superfund-related investigations and cleanup efforts, the Depot was divided into four Operable Units (OUs).
- OU-1 (Dunn Field, located north of the Main Installation, is the only known and documented burial area on the Depot)
- OU-2 (located in the southwestern quadrant of the Main Installation area and is characterized as an industrial area where maintenance and repair activities took place)
- OU-3 (the southeastern quadrant of the Main Installation area and contains the entire southeastern watershed and golf course)
- OU-4 (located in the north-central section of the Main Installation area where material storage took place.
Records of Decision (RODs), describing selected cleanup approaches to address site contamination not already addressed through previous cleanup actions, have been issued for all OUs.
An interim ROD to address ground water contamination was issued for Dunn Field (OU-1) in 1981.
The final ROD for the Main Installation (OUs 2-4) was issued in 2001. Major components of the cleanup approach included:
- Excavation, transportation, and off-site disposal at a permitted landfill of lead-contaminated soil located near the southeast corner of Building 949.
- Restrictions and site controls, which include, for example, prevention of residential land use on the Main Installation (except at the existing Housing Area).
- Enhanced bioremediation of chlorinated volatile organic compounds (VOCs) in the most contaminated portion of the contaminated ground water area.
- Long-term ground water monitoring.
The final ROD for Dunn Field (OU-1) was issued in 2004. Major components of the cleanup approach included:
- Excavation and off-site disposal of the contents of pits and burial trenches.
- Use of soil vapor extraction (a vacuum that extracts vapors in soil) to reduce VOC concentrations in subsurface soils to levels that are protective of the intended land use and ground water.
- Treatment of ground water underneath Dunn field through chemical injection involving zero-valent iron (ZVI).
- Installation of a permeable reactive barrier (a wall built below ground containing materials that trap harmful chemicals or change the chemicals into harmless ones) using ZVI to address high concentrations of contaminated ground water downgradient of Dunn Field.
- Use of monitored natural attenuation (natural processes to reduce contaminant concentrations) to address the portion of the contaminated ground water area that will remain downgradient of both active treatment zones.
- Long-term ground water monitoring.
- Implementation of land use controls.
A revised proposed plan and ROD amendment are planned in 2008/2009, which will document changes in the methods of soil and ground water treatment to achieve the cleanup action objectives of the 2004 ROD.
Cleanup Progress
In 1998, construction of a barrier well system was completed as an interim cleanup action for Dunn Field. In 2001, the well system was extended. The system has been in continuous operation since November 1998. Due to the system’s success in reducing ground water contamination to date, several wells have been shut down; the other wells may be shut down as early as 2009.
Between 1998 and 2001, several areas of contaminated soil were also excavated at the Main Installation and Dunn Field, through removal actions. One area was subsequently transferred for use as transitional housing for homeless veterans.
As part of cleanup efforts at the Main Installation, efforts have begun to identify residual sources of soil contamination that might be preventing the ground water cleanup action from being as effective as originally anticipated. DOD is also planning some enhancements (bio-augmentation) to the ground water treatment to speed up contaminant concentration breakdown..
Excavation of the burial pits, as specified in the 2004 final ROD for Dunn Field, was completed in 2006. Treatment of the VOC-contaminated sand and gravel layer beneath contaminant source areas using soil vapor extraction began in July 2007. Treatment of the VOC-contaminated silty clay zone (top 30 feet) using on-site thermal desorption (a process using heat to change chemicals into gases) began in May 2008 and is expected to be completed by 2009.
Approximately 9,000 pounds of VOCs have been removed from soil and ground water as a result of all cleanup actions.
Land use controls are in place for all cleanup actions.
The 2008 Five-Year Review (FYR) found that the cleanup approach for the site is expected to be protective of human health and the environment upon completion of cleanup actions for subsurface soil at Dunn Field and for ground water at both the Main Installation and Dunn Field. In the interim, human exposure to site contaminants that could result in unacceptable risks are being controlled and institutional controls are preventing exposure to, or the ingestion of, contaminated ground water.
Enforcement Activities
In 1995, EPA, TDEC, and the Depot entered into a Federal Facilities Agreement (FFA) with the DLA that outlined the process for site investigation and cleanup at the Depot under the Superfund program.
Community Involvement
EPA has conducted a range of community involvement activities at the Depot to solicit community input and to ensure that the public remains informed about site activities throughout the site cleanup process. Outreach activities have included public notices and information meetings on cleanup progress and activities.
Future Work
Soil and ground water treatment and related monitoring are ongoing.
The next FYR is required by January 2013.
Site Administrative Documents
Site Repository
For more information or to view any site-related documents, please visit the site information repository at the following location. As new documents are generated, they will be placed in the information repository for public information.
Administrative Record Index
For documents not available on the website, please contact the Region 4 Freedom of Information Office.