Chlorinated ethene contamination is present at hundreds of sites around the U.S. and threatens the health and quality of living in many communities. Complete reductive dechlorination of chlorinated ethenes to ethene is possible by the anaerobic bacteria Dehalococcoides mccartyi which uses H2 as an electron donor for the process. Microbial chain elongation (MCE) has recently shown viability as an H2 producing process for reductive dechlorination. This study examined the presence of native chain-elongating organisms in soil and groundwater samples from a Superfund site contaminated with chlorinated ethenes using batch microcosms experiments. The study’s findings have implications for the use of MCE to promote detoxification of chlorinated ethenes at contaminated sites.