Memphis Defense Depot
Site Summary ProfileEPA ID: TN4210020570
Location: 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 are underway
Human Exposure Under Control: Yes
Ground water Migration Under Control: Yes
Sitewide Ready for Anticipated Use: Yes
Site Reuse/Redevelopment: Portions of site in reuse / planned or actual reuses include residential, industrial, public, and recreational uses
Site Manager: Julie Corkran (firstname.lastname@example.org)
The Memphis Defense Depot (Depot) is a former warehousing and distribution center for the U.S. military where waste handling and disposal occurred. EPA, the Tennessee Department of Environment & Conservation (TDEC) and the Department of Defense (DoD) have undertaken a series of investigations and cleanup actions to protect human health and the environment. Three EPA-approved cleanup plans (Records of Decision, or RODs) have addressed all contaminants of concern, enabling the site to be returned to the community for reuse and redevelopment.
Although significant progress in reducing contaminant concentrations in groundwater at DDMT has been made, vertical and horizontal migration of contaminated groundwater within the Main Installation boundaries is not yet under control. The parties are working now to identify additional cleanup activities to prevent migration and restore the groundwater. No one at the Depot or off-site is exposed to the contaminated groundwater.
The DoD, EPA, and TDEC continue to ensure the protectiveness of the site’s remedy through long-term monitoring of ground water, land use controls, and required Five-Year Reviews of remedy performance. The summary sections below provide more details about the Depot’s history and current status.
The Depot is located at 2163 Airways Boulevard in Memphis, Tennessee. The Depot covers approximately 632 acres in a mixed residential, commercial, and industrial area of south-central Memphis. The Depot consists of two adjacent areas:
- Main Installation: An intensively developed 567-acre area with open storage space, warehouses, former military family housing and outdoor recreational areas.
- Dunn Field: An approximately 65-acre open storage and waste burial area.
The Depot is surrounded by small commercial and manufacturing businesses to the north and east and by single-family residences to the south and west.
Operations at the Depot began in 1942; the installation provided supplies, including clothing, food, medical supplies, electronic equipment, petroleum products and industrial chemicals, to the U.S. military. Hazardous substances were used and stored on site as part of Depot operations, resulting in soil and ground water contamination from leakage, spillage, disposal of out-of-date materials and normal application of pesticides. In 1946, the U.S. Army disposed of leaking mustard bombs at Dunn Field. Other wastes disposed of at the Depot included oil, grease, paint thinners, methyl bromide, pesticides and cleaning fluids. Storage and distribution of material continued until the facility closed in September 1997. Environmental assessment activities at the Depot began in the 1980s. The Depot was placed on EPA’s National Priorities List of contaminated sites in 1992. EPA, TDEC and DoD have worked collaboratively with the Depot Redevelopment Corporation (DRC) to enable the Depot’s cleanup, environmental restoration and reuse.
Threats and Contaminants
Contaminants of concern identified in ground water, sediment, soil and surface water include arsenic, dieldrin, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, tetrachloroethene (PCE) and trichloroethene (TCE)and carbon tetrachloride
Investigation and Cleanup Responsibility / Oversight
In 1995, EPA, TDEC and the Depot entered into a Federal Facilities Agreement (FFA) with the Defense Logistics Agency (DLA) that outlined the process for site investigation and cleanup under EPA’s Superfund program. DLA, a DoD agency and the former operator of the Depot, was the lead agency for cleanup and restoration activities. In December 2010, the Department of Army assumed responsibility from DLA for the remaining environmental restoration activities. DoD maintains overall responsibility for site cleanup and long-term stewardship with oversight provided by EPA and TDEC.
Site Cleanup Plan
The cleanup of contamination and environmental restoration activities at the Depot have been undertaken under both the federal Resource Conservation and Recovery Act (RCRA) and the Superfund law. Since early 2005, all activities have taken place under the authority of the Superfund program.
To assist Superfund-related investigations and cleanup efforts, the Depot was divided into four areas, or operable units (OUs).
- OU-1: Dunn Field, located north of the Main Installation, is the only documented waste burial area at the Depot.
- OU-2: Former industrial area located in the southwestern quadrant of the Main Installation where maintenance and repair activities took place.
- OU-3: The southeastern watershed and golf course, located in the southeastern quadrant of the Main Installation.
- OU-4: Former material storage area, located in the north-central section of the Main Installation.
EPA, TDEC, and DLA selected the remedy for the Depot in a series of RODs that addressed remaining contamination across all OUs.
EPA, TDEC, and DLA issued the ROD for the Main Installation (OUs 2-4) in 2001. The cleanup approach included the excavation and off-site disposal of lead-contaminated soil in a permitted landfill. Enhanced bioremediation was selected for the most contaminated portion of the ground water area, to be followed by long-term monitoring. To ensure the long-term protection of human health and the environment, land use controls were selected to restrict inappropriate future uses like schools and residential areas on portions of the Main Installation.
EPA, TDEC, and DLA issued the final ROD for Dunn Field (OU-1) in 2004. The cleanup approach included the off-site disposal of pit and burial trench contents, the reduction of VOC concentrations in subsurface soils, the use of chemical injections to treat ground water, and the installation of a below-ground barrier wall to trap or modify contaminants. Monitored natural attenuation was selected as the remedy for contaminated ground water located down gradient of both active treatments zones. Long-term monitoring was also selected as part of the remedy for all ground water. To ensure the long-term protection of human health and the environment, land use controls were selected to restrict inappropriate future uses on portions of Dunn Field.
EPA, TDEC, and DLA issued a ROD amendment for Dunn Field (OU-1) in 2009; the amended ROD documented several significant changes in the site’s remedy to better achieve the 2004 ROD’s cleanup objectives. The revised cleanup approach included the use of new technologies to address off-site ground water contamination and a targeted approach to addressing subsurface soils as well as the extent of chemical injections for ground water treatment. Excavation and off-site disposal were selected to address source materials in two areas with shallow impacts.
In 2010, the Depot achieved Construction Completion status and met EPA’s Sitewide Ready for Anticipated Use criteria. All remedies described in the RODs are either complete or the treatment systems are in operation and maintenance and long-term monitoring. Land use controls (LUCS) have been established for both the Main Installation and Dunn Field: compliance with LUCS is monitored and reported annually to ensure that only appropriate land uses are located at the Depot.
Third CERCLA Five-Year Review
In 2013, the third CERCLA Five-Year Review of the Depot cleanup was completed by the Army, TDEC and EPA. The purpose of the Five-Year Review is to evaluate the implementation and performance of a remedy to determine if the remedy is, or will be, protective of human health and the environment. The 2013 evaluation of the Depot remedy demonstrated that the cleanup continues to be protective of human health and the environment and will continue to be protective in the future.
- Third Five-Year Review, Defense Depot Memphis Tennessee, Final, January 23, 2013 (PDF)
Active treatment of groundwater contamination continues at both the Main Installation and Dunn Field. The Five-Year Review report identified two issues for consideration at the Main Installation (Operable Units 2-4):
- concentrations of PCE, TCE, and carbon tetrachloride have rebounded in the shallow (fluvial) aquifer since enhanced biological treatments were initially conducted in 2006-2009, and
- PCE and TCE are present in intermediate aquifer wells above the maximum contaminant levels allowed by EPA and TDEC.
Two actions are being taken to optimize the remedy and monitor progress toward groundwater cleanup goals at the Main Installation:
- Enhanced bioremediation treatments were restarted in November 2012 and continued through 2013, and
- the time projected to achieve groundwater cleanup goals will be reevaluated by DoD, EPA and TDEC in 2014.
Groundwater migration at the Main Installation is not yet under control. Monitoring data reviewed in 2014 indicated the vertical migration of contamination from the fluvial to the intermediate aquifer, horizontal migration of contaminants within the fluvial aquifer, and horizontal migration of contaminants in the intermediate aquifer to the property boundary at the northwest corner of the Main Installation. Eventually, attainment of cleanup goals in groundwater at Dunn Field and the Main Installation will be achieved. In the interim, exposure pathways that could result in unacceptable risks are being controlled and LUCs are preventing exposure to, or the ingestion of, contaminants of concern. In the long-term, protectiveness will be verified by periodic groundwater monitoring and LUCs.
In 1995, the Depot was placed on the list of DoD facilities to be closed under the Base Realignment and Closure (BRAC) process. The City of Memphis and Shelby County created the Depot Redevelopment Corporation (DRC) to plan and coordinate the reuse of the Depot. Since 1997, more than four million square feet of covered and uncovered facilities (96 percent of the Main Installation) have been returned to use, providing approximately 980 jobs. As of 2013, there are more jobs at the Depot than when the facility closed in 1997. With the exception of 24.5 acres on Dunn Field, all property at the Depot has been transferred for reuse. The remaining parcel is targeted for transfer through a competitive public sale in the near future. Actual or planned reuses include transitional veterans’ housing, a golf course, a police precinct, and the Memphis Depot Business Park.
In 1995, EPA, TDEC and the Depot entered into an FFA with DLA that outlined the process for investigation and cleanup activities at the Depot under the Superfund program. FFAs ensure coordination and scheduling of work priorities and ensure that concerned citizens have a voice in the cleanup for the life of the project. The Depot FFA remains in effect until all remedial action objectives and cleanup goals defined in the Main Installation and Dunn Field RODs have been achieved.
The Memphis Depot has conducted public participation activities throughout the site cleanup process. Activities have included Restoration Advisory Board (RAB) Meetings from 1994 to 2009, Community Information Sessions and public meetings, a regular newsletter, and the establishment of information repositories for the public. The RAB, comprised of a cross-section of community members, voted to adjourn in October of 2009 due to the final selection and implementation of all remedial actions. Future community involvement activities will be primarily related to significant remaining milestones, such as Five Year Reviews.
Groundwater treatment and long-term monitoring activities continue at the Main Installation and Dunn Field. Additional delineation of the extent of groundwater contamination at the Main Installation, along with expansion of the treatment areas and alternative technologies are being considered by the Army, TDEC, and EPA to address contaminated groundwater migration and accelerate the cleanup schedule. The next Five-Year Review of cleanup progress at the Depot is required in January of 2018. The public will be notified in 2017 of the opportunity to participate in the Five-Year Review process.
To view site-related documents in the Memphis Depot information repository, please contact the Memphis field office of the Tennessee Department of Environment and Conservation. As new documents are generated, they will be placed in the information repository.
Tennessee Department of Environment and Conservation
Memphis Environmental Field Office
8383 Wolf Lake Drive
Bartlett, TN 38133-4119
Contact: Mr. Jamie Woods