RESUMEN
It is well established that a large number of infectious diseases are transmitted primarily through water supplies contaminated with human and animal excreta particularly faeces. The purpose of the study was to assess bacteriological quality of drinking water in Lahore-Pakistan. It is a cross sectional descriptive study performing the Lahore city during the months of April and May 2008. A total of 530 water samples were collected from different localities of whole of the Lahore city. These represented areas with different socio-economic conditions. The samples were collected in sterilized containers and brought to the laboratory within two hours of collection. All the samples were tested for contamination with bacteria using multiple tube method to determine most probable number of total coliforms and faecal coliforms using standard procedure. Among 530 water samples, 197 samples [37.2%] were positive for bacterial contamination. It was observed that bacterial contamination was maximum in areas with low SEC [43.6%], followed by intermediate SEC [36.5%] and high SEC [22.9%]. The difference was found to be statistically significant [p<0.15] between areas with High and Low SEC while it was non-significant [p>0.5] between areas with Low and Intermediate SEC. Bacterial contamination is significant pro Hem in Lahore. Regular monitoring and chlorination/establishment of water filtration plants can improve this situation