An advanced oxidation process (AOP) for water reclamation, particularly groundwater remediation is described. It is based on a combination of ozone and electron beam irradiation. Main pathways of the hydroxy free radical generation in such a combination are reviewed and compared with those of other AOPs. New data is presented regarding the effect of the direct introduction of gaseous ozone into the irradiation chamber on pollutant decomposition, and the impact of the pH value on OH free radical production. Special attention is paid to an assessment of the combined ozone/electron beam process in comparison to other AOPs.