Drinking water quality surveillance in Hyderabad

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 Hyderabad City, Andhra Pradesh. It is a cross sectional descriptive study performing the Hyderabad city during the months of June and July 2011. A total of 50 water samples were collected from different localities of the Hyderabad 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 50 water samples, 20 samples (40%) were positive for bacterial contamination. It was observed that bacterial contamination was maximum in areas with low SEC (52%), followed by intermediate SEC (40%) and high SEC (10%). The difference was found to be statistically significant (p 0.5) between areas with low and intermediate SEC. Bacterial contamination is significant problem in Hyderabad City. Regular monitoring and chlorination/cleaning of water filtration plants and change of old water distribution pipelines can improve this situation.