A chemical works near Madrid had ceased operation and the site was in the process of being rehabilitated for future sale. The buildings were to be left in place but a targeted excavation was carried out to remove the high levels of soil contamination found in the vadose zone. Particularly high soil and groundwater contamination had been observed at, and just below, groundwater level.

In Situ Chemical Oxidation (ISCO) using RegenOx, was applied to target these and to avoid excavation into the saturated zone. The remediation goal was to reduce the residual contaminant mass that might otherwise form a secondary source on the site.