This project focuses on the chlorinated ethenes (CEs) contaminated sites. The purpose was to apply environmental forensic techniques, especially the compound specific isotope analysis (CSIA), for source identification at contaminated sites. The objectives of this project includes: (1) Collecting and reviewing the published literaturesand research reports about environmental forensics technologies, and providing a guideline for identification of CEs sources at contaminated sites. (2) Developing the CSIA analytical approaches for CEs compounds. (3) Investigating and characterizing the fingerprints of CEs products manufactured or used by domestic factories. (4) Evaluating the practicability of applying CSIA at domestic CEs contaminated sites. The achievements of this project included developing investigation guideline for identification of CEs sources at contaminated sites. We also successfully developed CSIA of carbon, chlorine, and hydrogen stable isotopes for the common contaminants in soil and groundwater, such as tetrachloroethene, trichloroethene, and vinyl chloride. Furthermore, the stable isotope and chemical fingerprints of several different domestic vinyl chloride manufacturers were studied by collecting their products, wastewater and wasted solvents. Despite different manufacturers may have similar chemical fingerprints, it was found that their stable isotope signatures were different and thus can serve as a fingerprint for source differentiation. As the ultimate goal of development CSIA is to provide critical information for source identification, four domestic sites contaminated by CEs were selected for practice. With the achievement of this project, the field-need oriented CSIA was developed and the results of field practice showed that this technique is promising and indeed can provide unique information about the sources.

Environmental Forensics Technology, Compound Specific Isotope Analysis, Chlorinated Ethenes Contaminated Sites