Site-specific conditions should be the ultimate factor in designing a permeable reactive barrier (PRB) remediation solution and the site performance and compliance monitoring plan should evaluate its operating effectiveness. Because the main goal of installation cleanup is to ensure that contamination is remediated and ultimately prevented from progressing further downgradient of the site, monitoring is needed to evaluate the capture and treatment efficiency of the PRB configuration. Since all current PRBs have somewhat different design configurations, it will be important to evaluate certain selected sites using a consistent approach. The purpose of this Department of Defense (DoD) Strategic Environmental Research and Development Program (SERDP) and Environmental Security Technology Certification Program (ESTCP) project and its two companion projects with the Department of Energy (DOE) and the Environmental Protection Agency (EPA) is to achieve combined Federal agency coordination in addressing these various performance and longevity issues at specific PRB projects. The DoD, EPA, and DOE projects are being executed simultaneously for a leveraged effort that will achieve maximum coordination to minimize duplication and to ensure that the most cost-effective measures will be implemented. Project coordination will ensure that data collected from each site are comparable, while allowing each agency to focus on its unique needs.

An typical PRB that would be evaluated for performance and longevity

This project is intended to focus specifically on the DoD sites only. The EPA and DOE will provide separate funding for their selected sites. Similar to the DOE and EPA projects, the DoD SERDP/ESTCP project approach will be conducted using the following tasks: (1) field monitoring survey and site selection, (2) performance sampling at selected PRB sites, and (3) performance data evaluation.

Over the last year the project has completed the field monitoring survey and site selection. The project has established regular conference calls with other DoD tri-Service partners and Remediation Technology Development Forum collaborators. The project also completed a demonstration site selection report that includes results from surveys from DoD, DOE, and EPA sites.

It is estimated that potentially 500 to 1,000 DoD sites could utilize the PRB technology. Using site-specific data from cost analyses performed at one Navy location, the results typically can represent most DoD sites. At Naval Air Station (NAS) Moffett Field in California, it would cost about $9 million to remediate the site by using a full-scale PRB over a 50-year period. Conversely, it would cost about $33 million over a 50-year period using the groundwater pump-and-treat method. Overall, it is estimated that the Moffett Field site can save about $24 million in contaminant plume remediation costs. It is reasonable to conclude that over the long term, billions of dollars could be saved at hundreds of sites contaminated by chlorinated compounds where the PRB technology can be applied.