Sustainability of water and wastewater treatment chemicals: development of Australian life cycle inventory data

Life Cycle Assessment (LCA) has been used in many parts of the water industry to quantify the environmental impacts of current and future water and wastewater infrastructure. It was included in the sustainability assessment framework published recently by the Water Services Association of Australia (WSAA). However, any LCA is as good as the data selected to develop it. Different Australian urban water LCA studies have used foreign, obsolete or poorly documented data in regard to the chemicals used in water and wastewater treatment. The lack of a consistent inventory dataset imposes a significant uncertainty on any LCA carried out in the Australian water industry. The Australian Life Cycle Inventory Database Initiative (AusLCI) aims to provide transparent and high quality data to the water industry in order to make carbon footprinting and LCA easier and more accurate for utilities. As part of this, the University of NSW, Chalmers University of Technology and six major water utilities serving over 63% of Australia’s population are collaborating in a three-year Australian Research Council Linkage project to better understand the amount of chemicals used in the water industry and their environmental profiles.This paper will provide the first results from the annual survey of operational data among our industry partners, identifying the key chemicals in water and wastewater treatment around Australia. It will recognise methodological norms for multi-product allocation, the choice of engineering or economic system models and the implications of attributional and consequential perspectives in the development of Life Cycle Inventory (LCI) data. Finally, it will demonstrate the environmental significance of chemicals in decision-making in water and wastewater treatment systems, and hence the importance of the sometimes neglected, so-called “scope 3 emissions” in carbon footprinting and other strategic environmental assessments