In December 2008 the first Danish field implementation of the ZVIClay soil-mixing remediation technology was initiated on a PCE DNAPL contaminated site. The technology ideally combines source zone degradation via zero-valent iron with a reduction of the saturated hydraulic conductivity via addition of bentonite clay. The degradation of PCE in the treated source area and the development in the downstream flux of chlorinated compounds have been monitored in six sampling campaigns. A PCE half-life of 50 days and a reduction of the average concentration of PCE of more than 99% were found during the first year. The main degradation product was ethene. The flux of chlorinated compounds through the downstream transect showed dechlorination. A 56% decrease in the flux of PCE and a corresponding increase in the flux of the degradation product cis-DCE were observed.