A triple bottom line approach to optimising odour removal from a residential water supply

Feedwater to Euroa Water Treatment Plant contains increasingly high levels of natural organic matter (NOM) which were determined to cause its strong earthy odour. A multidisciplinary approach was used to evaluate the coagulation process to better remove the taste and odour (T&O) causing organics from water supplied to the local towns. Such high levels of NOM require elevated doses of coagulant for removal, accounting for approximately 60% of the chemical costs. A need arose to reduce these operational costs. However, community expectations regarding T&O, and social and environmental impacts, are not typically considered in this process. The local water corporation, Goulburn Valley Water, undertook a case study involving a comparison of three coagulants to optimise the chemical coagulation process from a multidisciplinary (triple bottom line, TBL) perspective. The financial assessment incorporated operational costs and potential infrastructure requirements. The social assessment investigated the overall impacts on staff operating the water treatment plant and their broader community involvement. The environmental assessment focused on the impact on downstream infrastructure from changes in sludge volumes and wastewater quality, and third-party greenhouse gas emissions from chemical deliveries. From a TBL viewpoint, aluminium chlorohydrate was the most beneficial option.