The Defense Environmental Restoration Program was established by Congress in 1984 to evaluate and remediate sites that were contaminated as a result of Department of Defense (DOD) activities. The Commission received testimony from the office of the deputy under secretary of defense for environmental security about DOD's strategy for implementing a relative-risk-based ranking procedure for setting priorities among the sites that were to be addressed. This section discusses very briefly DOD's efforts to establish remediation priorities among its contaminated sites.

FINDING 6.6: The contaminated sites that DOD is legally bound to clean up are not all sites that pose the worst risks to health or the environment. DOD has developed a relative-risk ranking procedure to facilitate priority-setting among contaminated sites.

RECOMMENDATION: DOD should continue its efforts to establish risk-based remediation priorities among its contaminated sites in collaboration with community advisory groups.

RATIONALE

Listing procedures for the National Priority List establish entire DOD installations as single sites for the purpose of listing. DOD installations are generally large and varied, however, with locations of potentially high risk and locations of potentially low risk within a single installation. Since 1984, DOD has identified almost 20,000 potentially contaminated sites on some 1,700 current installations and about 8,000 potentially contaminated sites at formerly used installations in the United States. Given the large number and diversity of DOD's contaminated sites, a means to focus remedial activity that is consistent with relative risks to health and the environment was needed.

To assess relative risks at sites to help in the sequencing of remedial work, DOD developed the Relative Risk Site Evaluation Concept. The concept categorizes sites as of high, medium, or low risk on the basis of three factors: a hazard factor (a combined measure of contaminant concentrations in a given environmental medium), a migration-pathway factor (a measure of movement or potential movement of contaminants away from the original source), and a receptor factor (an indication of the potential for human or ecological contact with site contamination). A site's category can change because of new or additional information or as a result of cleanup activities. As in the Commission's risk-management framework, the rankings are performed in collaboration with community advisory groups at the sites. In practice, decisions about which sites should be addressed first include considerations in addition to the rankings, such as regulatory-agreement status and public health recommendations. A special consideration with regard to cleanup practices and community involvement arises at sites on the base closure list.

DOD's ranking procedure does not involve actual assessments of health risks, nor does it address the decision of whether work is necessary at a site. The procedure only provides relative-risk information for use in determining the sequence in which sites will be addressed.