Quantification of Interactions on Recharging the Brackish Aquifer using Cavity Type Aquifer Storage Recovery Well

Better understanding of mixing and geo-chemical reactions help in installation, operation and sustaining the aquifer storage recovery (ASR) system. Buffer storage volume (BSV) of 2000, 6000, 10,000 and 14,000 m³ were created in successive cycles of injection and recovery in a cavity-type brackish ASR well. Two-residence times of 13 and 70 days were allowed at a BSV of 14,000 m³. Calcite dissolution decreased with BSV and increased with residence time of 70 days. Groundwater quality of the recovered water was better than that of native water. Potassium concentration and temperature of the recovered water were more than that of injected water at all BSVs. Energy of 6.5 kJ was gained in one litre of the recovered water by raising the temperature of injected water from 27.5 to 29.05°C. Potassium and borate released from the illite and tourmaline minerals, respectively were 924 and 433 moles in 2000 m³ of recovered water at BSV of 2000 m³. The study has a potential of finding its application in conservation and better utilization of the scarce water resources in the semi-arid regions.