A sustainable and fully automated process to treat stored rainwater to meet drinking water quality guidelines

Exponential growth of water demand and a decrease in usable freshwater due to various climate, environmental and anthropogenic events make rainwater harvesting a useful practice. According to Australian health regulations, drinking rainwater is low risk, if the roof catchment, collection system and storage are well maintained. The CSU Engineering building, which has received an architectural award for its sustainable design, produces its drinking water (3.7L/person/day) within the premises. Rainwater is collected from the roof catchment, stored outside the building and treated on demand at a fully transparent water treatment plant installed at the entrance of the building. The water treatment facility is fully powered by solar panels installed on the roof. The treatment process consists of several operations, including aeration, sand filtration, GAC adsorption and UV disinfection. The performance of the CSU Engineering water treatment plant for the past 30 months is discussed in this paper. Primary and secondary water quality parameters of treated water were well within Australian drinking water quality standards and showed better results than municipal water available in the host town. The aeration unit improved secondary water quality standards (odor and taste) and the adsorption process was effective for elimination of metals. The result of this experiment indicated that this process could be a promising solution for providing safe drinking water in remote Australia, including sessional demands in rest areas and caravan parks.