Drinking water supply in rural Bangladesh mostly depends upon manually operated hand tubewells installed by the local community drillers. The occurrence of natural arsenic (As) in groundwater and its scale of exposure drastically reduced the safe water access across the country (Figure 1) and rendered tens of millions of people under health risk (Ahmed et al., 2004; von Brömssen et al., 2007). Tens of millions of people are exposed to concentrations above the national drinking water standard (BDWS: 50 µg L-1) and the WHO guideline (10 μg L-1) with visible manifestations of the toxic effects of long-term exposure to As, a well known carcinogen. The magnitude of the human tragedy will depend on the rate at which mitigation programs are implemented and, presently, the key challenge is to adopt a cost efficient and sustainable mitigation strategy that could be implemented for scaling up the safe water access.