Performance evaluation of aquifer storage recovery wells for conjunctive water management as influenced by buffer storage volume and storage time

摘要

Field experiments were carried out in a cavity type of aquifer storage recovery (ASR) well installed in an aquifer having highly saline native groundwater (EC = 28.4 dS per m). Good quality canal water (EC = 0.46 dS per m) was injected to investigate the effect of buffer storage volume (varying from 2000 to 14,000 cubic m) and storage time (varying from 2.5 to 70 days) on the recovery efficiency in five ASR test cycles. Field experiments with different ASR cycles showed that the recovery efficiency increased with increasing buffer storage volume and decreased with increasing storage time. For buffer storage volume of 14,000 cubic m and storage time of 13 days, the observed instantaneous recovery efficiency (IRE) and integrated recovery efficiency (CRE) at the target water quality of 2 dS per m of the recovered water were 80.2 and 108% respectively. At the test site it was observed that a buffer storage volume of 14,000 cubic m was essential to create a buffer zone of good-quality water between native saline groundwater and reusable freshwater zone to achieve a good recovery efficiency of injected water after a storage time of 70 days. The ASR technique was found practically feasible and economically viable for reclamation of groundwater quality under shallow water-table condition.