From field trials to policy implications Abhijit Mukherjee (IN) & Ravi Naidu (AU) Groundwater arsenic mitigation in Bangladesh: Mission achievable or impossible?

Arsenic occurs mostly in the shallow Holocene grey aquifers where concentration can reach to a maximum of more than 3000 μg L−1. The yellowish to reddish brown Pleistocene aquifers are characteristically low in arsenic as in the capital city Dhaka. Arsenic occurs mostly in the southern deltaic plains and in some areas almost all shallow wells can exceed the limit. In other contaminated areas there are large small scale variability in arsenic concentrations even at smaller scales. Reductive desorption or dissolution of arsenic from iron phases is considered as the principal mechanism for mobilization of arsenic in groundwater.