On a 6 hectare site in northern Italy, an extensive enhanced reductive dechlorination process had been previously been carried out by REGENESIS using a combination of proprietary electron donors (3-D Microemulsion and HRCs). This resulted in successfully reducing TCE contamination and its daughter products from high levels (suggesting the presence of some DNAPL) to low dissolved phase concentrations. The concentrations were suitably low to allow regulatory closure of the internal part of the site. This was achieved within 2 years from a single injection. Immediately beyond the downgradient site boundary, a river presents a sensitive receptor. This, plus legislative rules, determine that the site boundary targets are very stringent (<1 μg/L). Although the previous electron-donor application has reduced the contaminant influx dramatically, at such low concentrations, biodegradation alone may not reach these low targets.