A service station in Hertfordshire, UK had soil and groundwater contamination from petroleum hydrocarbons. A remedial strategy used pumping and treating (P&T) combined with chemical oxidation using RegenOx and biological treatment with ORC Advanced. This integrated approach reduced contamination levels faster and more cost effectively than P&T alone, lowering the treatment time from an estimated 12 months to 6 months. Monitoring showed an average 99% reduction in total petroleum hydrocarbons, meeting the target level of 10 mg/L across the site.