Rapid degradation of contaminants by the injection of a strong oxidant (either Fenton’s Reagent, neutral pH equivalent or Potassium Permanganate) in aqueous solution. The process is hydraulically controlled to maximise the radius of influence. The breakdown/end products (O22 and CO2) and any unoxidised daughter products are recovered under vacuum. This process is very rapid and very powerful providing an aggressive treatment for high concentration source zone hot spots. It is most effective in higher permeability aquifers but can be utilised in lower permeability soils in combination with hydrofracturing.