Sustainable Arsenic Mitigation (SASMIT): An approach for developing a color based tool for targeting arsenic-safe aquifers for drinking water supply

Presence of high concentration of geogenic arsenic (As) in water and soil become a big health risk towards millions of people in various magnitudes through drinking water. To minimize arsenic interaction with human considered as a global challenge. The main objective of this research is to develop a simple, easy and cost-effective arsenic identification tool which would be easily acceptable by the inhabitants and local well drillers. The relationship of sediment color and corresponding As concentrations in water has already been demonstrated and is being further studied under SASMIT project. A total of 1920 sediment samples from 15 locations bored up to a depth of 250 m have been scientifically evaluated according to the color codes using Munsell Color Chart. A total of 60 varieties observed and simplified into four color groups viz. black, white, off-white and red. It is revealed that red and off-white sands can be targeted for As-safe water. White sands can also be safe but uncertainty is high and black sediments produce water with highest As concentration, although Mn content in waters sampled from white and black sediments is relatively low. Further refinement is going on for improving the tool for targeting aquifers which can be safe for both arsenic and manganese.