Abstract. Collection of shallow groundwater and injecting it into the underline Miocene aquifer is a great environmental problem on the groundwater resources at El Obour city and environs. The present research work aims to investigate this water quality and validity of photocatalytic treatment of polluted water using nano-titania in presence of solar radiation. Twenty-eight representative samples were collected from various locations and their physical, chemical and microbial characteristics were determined. Bacteria analysis has been investigated for the presence of total bacterial count and indicator bacteria include total coliform, fecal coliform and fecal streptococci. The heavy metal analysis shows that more than 85 % of the samples could be used for drinking in comparison with WHO specification for drinking water. The main pollutants in these samples are Cd and Pb. All the studied samples contain a viable count of heterotrophic bacteria, total coliform, fecal coliform and fecal streptococci, indicating the contamination with human and animal fecal material. The high number of indicator microorganism counts observed reflected the poor quality of water. The photocatalytic technique shows high efficiency towards the removal of more than 95 % and 82 % of microbial pollutants and organic residuals; respectively.