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 literatures and research reports about natural degradation and remediation cites technologies, and providing interpretation methods. (2) Investigating and characterizing the fingerprints of CEs various sources, and evaluating the mother compound identified methods. (4) Investigating the stable isotope fingerprints change of pollutants through mass transformation, and evaluating the feasibility of the comparison in environmental matrix. (5) Based on actual needs of EPA, investigation and identification of CEs sources at contaminated sites. (6) Developing and manual for identification of CEs sources zone at contaminated sites.and the guideline for CEs sources identification at contaminated sites with CSIA. The achievements of this project included developing guideline for CEs sources identification at contaminated sites with CSIA and manual for identification of CEs sources zone at contaminated sites. We also successfully developed CSIA of carbon, chlorine, and hydrogen stable isotopes for the selected chlorinated organic solvents in different sources, evaporation, sorption and dissolution. 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.

chlorinated hydrocarbon, environmental forensics, stable isotope