Bacteriological assessment of aquifer storage and recovery (ASR) water in southwest coastal Bangladesh

Safe drinking water is scarce in southwest coastal Bangladesh. Harvested rainwater and rain-fed pond water are the main sources of drinking water for people living in this area. Both government and non-government organizations are promoting aquifer storage and recovery (ASR) schemes to provide safe drinking water for this population. This study assessed the bacteriological quality of both source water and abstracted water from five ASR sites. Water sampling and laboratory analysis for indicator bacteria and physico-chemical parameters were conducted once every 2 months, over a period of 1 year. Samples were taken from source ponds, abstraction wells and household storage containers (point of use) for each of the ASR sites. Although the water from abstraction wells showed a 97% and 82% lowering of E. coli and Enterococci counts, respectively, from that of the source ponds, they did not satisfy the WHO drinking water standard. Moreover, the microbial quality of the water deteriorated at the point of use. This indicates the requirement for both in-house treatment and improved hygiene practice for consuming ASR water.