Vinyl chloride (VC) is a common groundwater contaminant and known human carcinogen. Conventional treatment strategies are both difficult and costly. Aerobic bacteria readily and completely detoxify VC under laboratory conditions. Unfortunately, the role of these organisms under real world conditions is poorly understood. The goal of this research is to combine molecular biological tools and conventional microbiology techniques to provide a more complete understanding of how aerobic VC degrading bacteria behave under field conditions.