Speaker Name(s): Elizabeth A. Edwards, Ph.D., P.Eng. Description: Groundwater contamination is a serious threat to global health and prosperity. Chlorinated solvents are among the most common groundwater contaminants. Owing to their toxicity, even small spills usually render groundwater unsuitable for use, and cleanup is typically a costly and long-term undertaking. Bioremediation can be low cost and effective, but must be deployed scientifically. Recently, a fascinating group of subsurface microorganisms, called Dehalococcoides, has been discovered that can dechlorinate the common solvents tetra-chloroethene and trichloroethene to the benign product ethene. Remarkably, these organisms obtain energy for growth from dechlorination. The intriguing microbial physiology of Dehalo cocccoides will be described, with emphasis on how this physiology is critical for the success of chlorinated solvent bioremediation.