Groundwater conditions in the multi-aquifer system in the Krishna River Delta, India, were studied through an integrated approach using hydrochemical, hydrogeological and isotopic techniques. This study
was taken up because of the reported seawater intrusion into the groundwater system of this agriculturally rich region. The results, of hydrochemistry and environmental tritium including the radiocarbon dates,
indicate that the origin of salinity in the aquifer systems is due to palaeo-geographical conditions.

http://www.ias.ac.in/currsci/10apr2011/1032.pdf