ABSTRACT
The use of reclaimed water in aquifer storage and recovery (ASR) is an important tool for water sustainability in arid regions. The demand on groundwater is reduced and abundant resources, such as storm water or sewage effluent, are utilised. A field trial at Bolivar, South Australia is investigating the viability of reclaimed water ASR in a limestone aquifer. Injection of 250 ML reclaimed water was followed by approximately 16 weeks of storage with subsequent recovery of 150 ML. Upon commencement of injection both aerobic organic matter oxidation and denitrification were observed within a 4m radius from the injection well. In contrast, the storage phase was indicative of higher microbial activity centred at the ASR well. Sulphate reduction up to 1.5 mmol L−1 was evident in water sampled from the ASR well while sulphate concentrations at the 4m radius remained constant. Buffering by dissolution of calcium carbonate was evident during both the injection and storage periods.
