ABSTRACT
Three increasing volumes of canal water (128, 346, 2520 m3) were injected in successive cycles of injection and recovery in a retrofitted cavity type aquifer storage recovery (ASR) well in brackish groundwater. The mixing percentage for all water quality parameters increased as more water was recovered, except for calcium which remained virtually constant. The recovery efficiency was over 55%, increasing linearly with the volume injected. Calcium dissolution from calcite and potassium release from illite clay was 49 and 45 per cent above the mixing ratio determined from chloride. In this process 29 % of hydrogen ions were consumed. Other cations and anions had concentrations within the range determined for mixing of conservative solutes. During the winter season, the recovery water temperature increased from 11 °C of the canal water to 22°C of the native groundwater.
