<![CDATA[This review of the impact of large-scale pumping on arsenic distribution reveals that groundwater-fed irrigation and domestic withdrawal impart tremendous stress on the limited groundwater resource base and disrupts the dynamic equilibrium of the groundwater system of the Ganges–Meghna–Brahmaputra (GMB) delta in Southeast Asia. Excessive groundwater extraction through pumping affects the groundwater quality in three major ways. First, excessive pumping transports atmospheric oxygen and organic-rich surface water to the subsurface. Second, it promotes arsenic build up in surface soil irrigated with arsenic-laced groundwater. Finally, it shifts groundwater replenishment zones lying at various depths near extraction points, thus, carrying dissolved arsenic from shallow Holocene paleo-channel aquifers to deeper paleo-channel aquifers of the Pleistocene age. Optimal management for safe and sustainable groundwater exploitation operations in the area must aim to ameliorate the deleterious impacts of pumping on groundwater quality through either technological or policy intervention.]]>
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