Comparative Sustainability Assessment of End-of-Life Resource Recovery Strategies for Water Meters

Abstract

Water meters are crucial parts of the world's water supply systems, enabling households and industries to measure water consumption. These everyday items have developed in design, material composition, functional capabilities, and durability. The meters within the Dutch industry are primarily made from brass bodies with plastic internals and top parts, but this has changed in recent years due to regulations and industry trends. Water meters have an End of Life (EOL) of around 20 years. Once they reach the end of their operational life, they are replaced by new water meters.

From a sustainability perspective, old water meters require a sustainable recovery strategy. From the academic literature and the drinking water utility (DW) point of view, little is known about what happens with the water meters once they leave the warehouses, where they are piled up until they are picked up by the resource recovery (RR) facilities. The EoL resource recovery strategies of these meters remain unexplored. This absence of information leads to incomplete knowledge of the impacts of the meter's sustainability after decommissioning. Addressing this gap is essential for developing sustainable future strategies for water meters.

Through exploratory field research, this research aimed to first map out the current water meter assets, the ongoing trends and the EoL RR strategies of water meters and consequently assess and evaluate the sustainability of these current strategies given the different water meters used for this study to provide a broader perspective on how future proof these strategies are given the trends in the water meter industry.

A Life Cycle Sustainability Assessment (LCSA) is used with varying boundaries for the sustainability pillars to assess the sustainability of the different resource recovery strategies. It follows an attributional, comparative assessment, where the EoL RR strategies of manual disassembly (MD) and mechanical shredding (MS) for the selected water meters: brass-bodied meters (representing currently decommissioned models), plastic-bodied meters (reflecting current industry trends), and smart meters (aligning with future industry goals) are assessed and evaluated from a weak sustainability interpretation.

From an environmental perspective, the study’s findings suggest that differences in EoL RR strategies substantially impact brass-bodied water meters. Smart meters also display relatively high environmental sensitivity due to their incorporated electronics, while plastic-bodied meters show only minor variations. The study's findings also highlight the contribution of the different materials used in these meters, considering their life cycle.

Economically, the potential fluctuations in material yield outcomes make the choice of strategy for brass-bodied meters especially important. Minor amounts of content loss can have a significant financial impact on the potential scrap revenue. While MD remains stable and beneficial for brass-bodied meters, it becomes less attractive for plastic and smart meters due to lower scrap values and comparatively higher operational costs than MS.

Socially, the assessment remains open to interpretation: MD promotes greater inclusivity and job opportunities yet involves more physical exertion and potential fatigue. MS streamlines the process, reducing labour time and ergonomic strain but offering fewer inclusive employment possibilities.