Radiocarbon dating of groundwater along suspected paleochannels in Pyayagraj, Uttar Pradesh, India

Proper understanding of the impact of paleochannel network on groundwater recharge can help in planning effective measures for groundwater replenishment. Paleochannels are old/buried sand deposits which can act as good conduits for rainwater infiltration. Considering the growing concerns on groundwater level depletion in Central Ganga Basin, an isotope investigation was carried out in Prayagraj, Uttar Pradesh to assess groundwater dynamics along suspected paleochannels. A total of 14 samples were collected for radiocarbon measurements from tube wells tapping different depths. In the field, the dissolved inorganic carbon (DIC)is collected from about 60 L of water by precipitating in the form of barium carbonate. In the laboratory, the precipitates were treated with phosphoric acid under vacuum to release carbon dioxide, which is absorbed in carbasorb scinitallator mixture and counted in liquid scintillation system for 1000 minutes