Alternative Water Supply Options

The sources of water available in Bangladesh for development of alternative water supplies are groundwater, surface water and rain water. An estimated 29 million people, exposed to arsenic contamination in excess of 50 µg/L through 27% contaminated shallow tubewells and few production wells in urban centers, will require alternative water supply. Four groundwater based options, six surface water based options and few rainwater harvesting techniques have been experimentally adopted as alternative water supply options in Bangladesh. On the other hand, thirty community and household level arsenic removal technologies have been tried in Bangladesh to reduce arsenic contents of water of contaminated tubewells to acceptable levels. Deep tubewells, dug/ring wells, treatment of surface waters and few arsenic removal units show good potentials for water supply in arsenic affected areas and are suitable for adoption in the national program. Most options are site specific and no single option can provide arsenic safe water in all areas or to people having wide variation in socio-economic conditions. Piped water supply, irrespective of source should be given priority where feasible considering convenience and better quality control. Rainwater harvesting has good potential at household level but a system completely based on rainwater appears to be too costly and the method is yet to be popular in Bangladesh. Standard manuals should be developed for all options for uniformity in practice.