[Application Case of Accurate Site Investigation with Life-Cycle Conceptual Site Model Development].

A life cycle conceptual site model (LC-CSM) can represent the actual spatial distribution and migration of pollution of a site very accurately and be beneficial in supporting decisions for accurate site remediation or risk management. A volatile chlorinated hydrocarbon contaminated site in the Beijing-Tianjin-Hebei region was chosen as the study case. LC-CSMs were established following the site assessment, preliminary investigation, detailed investigation, and supplementary investigation of each stage. The application of field screening tests such as a membrane interface probe and the multi-electrode resistivity method assisted in identifying potential pollution sources and hot points. Concurrently, a large amount of vinyl chloride, the end product of chlorinated hydrocarbon degradation, was detected in some boreholes, indicating that pollutant biodegradation had occurred at this site. Some typical boreholes and cross-sections were chosen to analyze the biodegradation indicators and chemical fingerprints, combining the results of the comprehensive score of chlorinated hydrocarbon anaerobic biodegradability in groundwater reaching 22. It is judged that the site has strong anaerobic biodegradability. This step-by-step optimization forms an LC-CSM for site investigation, which provides scientific support for accurate site characterization.