Add to ORKGWhen iron is used as the active agent in subsurface remediation of chlorinated solvents (i.e. permeable reactive barriers, PRBs), corrosion is a necessary part of the chemical process and can cause precipitates to form on the iron surface thus leaving the PRB less effective and can even alter groundwater flow around the structure. Ultrasound was examined for three years in laboratory studies before attempting to use it in a field application. Since the initial field demonstration at Launch Complex 34, Cape Canaveral Air Station, Florida, ultrasound was used at two other PRB field sites. Results show that ultrasound application improves half-lives from 21-67% (dependent on transducer power and duration of exposure) over untreated iron sample...