High-Resolution Carbon Accounting Framework for Urban Water Supply Systems

Decarbonization of urban infrastructure systems is imperative to meeting global climate goals. Urban water supply systems (UWSSs) account for 1-3% of urban electricity consumption in the U.S., a value expected to increase, as municipalities tap nontraditional water supplies that are either more distant or require more energy-intensive treatment. Reducing the carbon intensity of UWSSs will require a combination of infrastructure upgrades, operational modifications, and behavioral interventions, but urban water planners, water treatment system operators, and consumers lack transparent tools for quantifying the carbon emission implications of these decisions. We propose a high-resolution carbon accounting framework that allows for attribution of carbon emissions to individual water sources, water system components, or individual consumers in a UWSS. The high temporal resolution of this framework also enables rapid assessment of the potential for operational and behavioral interventions to reduce the carbon intensity of UWSSs. We demonstrate this carbon accounting framework on a real-world UWSS serving a city of roughly 100 000 residents. The high spatial and temporal resolution, coupled with the scalability of this approach, makes it a valuable tool for consulting engineers, operators, and consumers seeking to deliver Net Zero water supplies.