PUBLIC HEALTH ASSESSMENT
USA DEFENSE DEPOT MEMPHIS
MEMPHIS, SHELBY COUNTY, TENNESSEE
The environmental routes, as shown in Figure 1 have been evaluated by ATSDR , using environmental information collected during the remedial process. The following are conclusions reached by the ATSDR following this evaluation. The numbers refer to the numbers of the routes as shown in Figure 1.
- Water from the shallow aquifer under DDMT is not used for domestic purposes. Memphis\Shelby County has provided municipal water for DDMT and neighbors since the 1940s -1950s. Current monitoring procedures sufficient protect of public health from contaminants, including those that might migrate the shallow aquifer contamination under DDMT. As a part of the remediation process DDMT is planning to pump and treat groundwater to halt migration of the contaminated shallow groundwater plume.
- Controls enacted by DDMT in 1986 have greatly restricted, if not completely eliminated,
the possibility of contact of people with contaminated water in Golf Course Ponds.
Contamination present in water bodies within the base golf course does not represent a hazard to
public health. There is no information on past exposure. However, the short term exposure that
would have occurred could not be expected to cause significant health problems.
The onsite drainage ditch water contains low levels of VOCs, metals, petroleum products and pesticides. These levels are not sufficient to cause a threat to public health from dermal contact. Additional sampling scheduled for summer of 1995 will provide further information.
- The onsite drainage ditch sediment contains low levels of VOCs, metals, petroleum products and pesticides. These levels are not sufficient to cause a threat to public health. Additional sampling scheduled for summer of 1995 will provide further information.
- There are currently no air emissions occurring at DDMT that are a threat to public health.
Information is needed on extent of surface soil contamination resulting from sandblasting operations at DDMT. This information will address the issue of possible offsite air transport of metals from these operations.
- Localized soil contamination exists within the boundaries of DDMT. DDMT has limited access to these contaminated areas so as to sufficiently reduce possible exposure to the public.
- Home gardens in the area have probably not been exposed to high enough amounts of chemicals from DDMT to have received by the fruit or vegetables. It is unlikely that large amounts of contamination have been present in either the soil in the areas where gardens have been grown, or in the ditch water that might have been used to irrigate these gardens. During the years before municipal water was supplied, Dunn Field disposal records show very little contaminant that could have reached groundwater or private wells. Finally, most of the chemicals that might be present are not easily taken up by dermal contact.
Community concerns have been expressed about public health effects: from contamination in drainage ditches and from food grown in areas near these ditches; from contaminated groundwater; and from mustard gas destroyed and disposed at DDMT in 1946, as well as other chemical agents disposed at Dunn Field.
ATSDR Conclusion Categories of No Apparent Public Health Hazard have been assigned to all of the environmental routes. Table 3 provides additional details on each of the routes.
-- * "controlled" means that institutional controls (fences, paving, other measures) have eliminated possibility of significant exposure. ** -- "exposure unlikely" means that significant exposure (resulting in public health problem) to hazardous chemicals not likely to occur.
The Comprehensive Environmental Response Compensation, and Liability Act (CERCLA; also known as Superfund) as amended, requires ATSDR to conduct needed follow-up health actions in communities living near hazardous waste sites. To identify appropriate actions, ATSDR created the Health Activities Recommendation Panel (HARP). HARP has evaluated the data and information contained in the DDMT Public Health Assessment for appropriate public health actions. HARP determined that health education and health studies follow-up actions by ATSDR are not warranted. There do not appear to have been exposures in the past which resulted in public health problems, and there are no current exposures.
- Access should continue to be restricted to all areas with known contamination until remediation is completed.
- To further assess the potential of offsite surface water and sediment contamination, ATSDR recommends that the DDMT sampling programs should include provisions to sample sediment from drainage ditches near to and beyond the base boundaries, including west and south of the Main Installation and west of Dunn Field. This sampling and analysis will address major concerns on the part of neighbors to DDMT.
- To further assess the possible contamination from the sandblasting areas, ATSDR recommends that the DDMT sampling programs should include provisions to sample soil at the base boundary between the neighboring residences and the sandblasting operations.
- ATSDR recommends that DDMT undertake to verify, to the extent possible, the completeness of records concerning waste disposal at Dunn Field. If additional records are located or if environmental evidence of additional disposals is found during RI activities, ATSDR will provide an evaluation of public health impacts.
- ATSDR recommends that DDMT continue close cooperation with USACDP and CDC over safety procedures concerning remedial operations that may encounter chemical agents disposed at Dunn Field.
- ATSDR will evaluate analytical data from the sampling as described above.
The public health action plan (PHAP) for the Defense Depot Memphis Tennessee NPL site contains a description of actions to be taken by ATSDR and/or other governmental agencies at and in the vicinity of the site subsequent to the completion of this public health assessment. The purpose of PHAP is to ensure that this public health assessment not only identifies public health hazards, but provides a plan of action designed to mitigate and prevent adverse human health effects that would result from any exposure to hazardous substances in the environment. Included is a commitment on the part of ATSDR to follow-up on this plan. The public health actions to be implemented are as follows:
- Groundwater pumping and treatment is planned for the shallow aquifer under DDMT.
- ATSDR will continue to coordinate with DLA, EPA and state agencies to assure that recommendations are implemented.
- DDMT will collect and analyze water and sediment samples from drainage ditches that extend past base boundaries, as a part of ongoing RI activities.
- DDMT will collect and analyze soil samples from the vicinity of the base boundary near the sandblasting operations at Building 972, as a part of ongoing RI activities.
- DDMT will coordinate with USACDP and CDC on safety procedures during remedial operations that may encounter chemical agents disposed at DDMT.
- ATSDR will review the remedial activities at DDMT, to evaluate the proposed remediations in relation to protection of public health. ATSDR comments, and recommendations, as appropriate, will be provided to EPA, the DLA and State of Tennessee.
- MLG&W will continue to monitor for DDMT-related contaminants at the city wells in the vicinity of DDMT.
ATSDR will reevaluate and modify the Public Health Action Plan as needed. New relevant data, or the results of implementing the above proposed actions may determine the need for additional actions at this site.
Environmental Health Scientist
Army Section, Federal Facilities Assessment Branch
Division of Health Assessment and Consultations
Agency for Toxic Substances and Disease Registry
ATSDR Regional Representative
Senior Regional Representative
ATSDR Regional Operations, Region IV