Site Characterization to Support Permeable Reactive Barrier Design

Careful design studies and selection of an effective technique for the installation of permeable reactive barriers (PRBs) are important contributors to the overall success of zero-valent iron PRBs. This article provides a case study summarizing the successful design and construction of a PRB installed at the former Carswell Air Force Base located in Fort Worth, Texas. Expedited site characterization using a cone penetrometer rig equipped with a mass spectrometer was employed to provide real-time characterization and lithologic data. These data proved to be in-valuable for the design of the PRB and allowed for the development of an accurate precon-struction cost estimate. Field data gained from the expedited water quality and geologic characterization along with aquifer testing and a bench-scale treatability study provided a comprehensive basis for the design. The biopolymer slurry construction technique provided additional unanticipated benefits to the designed zero-valent iron treatment by promoting the development of anaerobic conditions favorable for microbial degradation of trichloroethene. Postconstruction monitoring data are discussed to illustrate the successful performance of the PRB. (C) 2005 Wiley Periodicals, Inc.