ABSTRACT
Brown sand aquifers (BSA) have been suggested as potential target for safe drinking water abstraction due to low levels of arsenic (As) (von Brömssen et al. 2007). These aquifers are in many instances isolated by an impermeable red clay layer (Pal and Mukherjee 2009) which protects the vertical recharge of As rich groundwater from the overlying Grey Sand Aquifers (GSA) along with organic carbon responsible for reductive dissolution of metal hydroxides (von Brömssen et al. 2007). These BSA sands have high As adsorbing capacity (Robinson et al. 2011). However, before advocating for BSA as an alternative source of safe drinking water on a mass scale, it is essential to investigate its long term sustainability by i) delineating its regional distribution and ii) diagnostic hydrogeochemical contrast with the GSA.
