I.4 Aquifer characteristics and mobility and transport of arsenic Flushing of arsenic from aquifer: Implications for safe drinking water options in high arsenic occurrence areas

An intriguing characteristics emerged from studies of groundwater As distribution is the spatial variation on various scales (1-100 m) and with depth (van Geen et al., 2003). That low As groundwater and aquifer(Zheng et al., 2005) can be found in areas where As occurrence is prevalent has led to mitigation strategy such as well switching (van Geen et al., 2002) and installation of community wells (van Geen et al., 2003) to low As aquifer. Thus, there is a need to better understand the hydrogeological and biogeochemical factors that permit the sustainable usage of low As aquifers (Michael & Voss, 2008). This paper discusses these factors using case studies from Bangladesh and points out future research need to help identify low As aquifers in high groundwater As areas.