Delineation of multiple chlorinated ethene sources in an industrialized area--a forensic field study using compound-specific isotope analysis.

Identification of polluters and the allocation of contaminant sources are key tasks when evaluating complex subsurface contamination with multiple and overlapping plumes, as frequently found in industrial areas. Under certain conditions, compound-specific stable isotope analysis (CSIA) may provide decisive information in such environmental litigation studies. Here, we present an illustrative case study highlighting the potential and limitations of using delta13C values of halogenated hydrocarbons (tetrachloroethene and its transformation products) as a keytracer for discriminating different contaminant sources, even in the presence of biodegradation and a complex hydrogeology.