16S rRNA gene sequencing revealed the bacteria community present in a groundwater plume contaminated with PCE, TCE and vinyl chloride. The focus of this study is a contaminated site in Carver, MA. This site contains a dilute VC plume (2-27 μg/L) where bioremediation technologies (e.g. molecular oxygen injection) were implemented to stimulate aerobic microorganisms that could cometabolize VC. This site is unique in that ethene gas was also injected into the groundwater in an effort to biostimulate etheneotrophs.