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Enhancing drinking water resilience has become increasingly important. However, a comprehensive analysis of drinking water emergency countermeasures is lacking. This study evaluated eight countermeasures including monitoring, local alternatives, reclaimed water, interconnection, bulk water, pre‐packaged water, emergency treatment, and isolation valves from resilience and sustainability (i.e., life cycle cost) perspectives. While countermeasures such as interconnections perform relatively well from both perspectives, there is a clear trade‐off between resilience and cost. Local alternatives and emergency treatment respond quickly and provide sustained supply during emergencies but may incur higher costs. Bulk water and pre‐packaged water are typically inexpensive but have limited supply capacity and take time to distribute. As future threats are likely to become more frequent and prolonged, it is prudent for service providers to invest in countermeasures that perform well in both resilience and cost and use an integrated approach that combines high capital projects with bulk/pre‐packaged water contracts.

 

Urban wastewater service provision is an important energy consumer as well as a potentially important energy producer. This study aims to advance understandings on the influence of climate change on the intra- and inter-annual patterns of wastewater treatment plants’ net life cycle energy consumption. Historic monthly operational data of a wastewater treatment plant in the northeast United States were obtained and its current net life cycle energy demand was investigated. Comprehensive multivariate and multiple linear regression analyses were then performed. The main climate variables (temperature, rainfall, and snowfall) and the wastewater characteristics (flow rate, water temperature, total suspended solids, 5-day biochemical oxygen demand, and chemical oxygen demand) were used to develop regression models for energy that is directly and indirectly consumed and generated at the treatment plant. Two different approaches, a lumped and a month-based method, for conducting the regression analysis were investigated. Whenever possible, these two approaches were combined to improve the predictive power of the regression models. The obtained result shows the treatment plant’s direct energy use consists of more than 86% of the total energy consumption currently. Various energy recovery strategies allow the treatment plant to offset more than 15% of its total energy consumption. The future annual wastewater influent of the plant was projected to decrease towards the end of the century under climate change, with a significantly larger seasonal variation. The influent wastewater quality is projected to decrease, leading to higher direct and indirect energy consumption for treatment. Projections of future intra-annual responses show that the seasonal variations of wastewater flowrate as well as the monthly cumulative energy demand can potentially experience a two-fold increase, resulting in more frequent system shocks and create operational difficulties.