Several programs have been undertaken during the last few years to install rooftop rainwater harvesting systems as an alternative drinking water supply source both in the coastal and arsenic affected areas in Bangladesh. In this study, quality of the harvested rainwater used for drinking water supply was assessed. A total of 308 harvested rainwater samples were collected from the different storage reservoirs located both in coastal and arsenic affected areas and analysed for various physical, chemical and microbial indicators. Most of the physical and chemical water quality parameters were well below the Bangladesh Drinking Water Standard and WHO guideline values. However, the harvested rainwater was found microbiologically contaminated to some extent and the water is not suitable for consumption without treatment. For safe and sustainable rainwater harvesting, WHO guideline and water safely plan (WSP) can be adopted in Bangladesh.
Keywords: drinking water, microbial indicators, rainwater harvesting, suitability, water quality