Decentralized water collection systems for households and communities: Household preferences in Atlanta and Boston.

Development of sustainable and resilient water infrastructure is an urgent challenge for urban areas to secure long-term water availability and mitigate negative impacts of water consumption and urban development. A hybrid system that combines centralized water infrastructure and household decentralized water facilities, including rainwater harvesting and greywater recycling, may be a solution to more sustainable and resilient water management in urban areas. Understanding household and community preferences for decentralized water facilities is important to inform the design and ultimately the promotion and adoption of such systems. In this study, we conducted a discrete choice experiment, via Amazon Mechanical Turk, to collect data on household choices of different decentralized water facility designs in two U.S. cities, Atlanta, Georgia and Boston, Massachusetts. Based on the responses to the choice experiment, we then developed a latent-class choice model to predict households' preferences of decentralized system design features and examine the influence of socioeconomic and personal characteristics on heterogeneous class membership. We identified six major classes of preferences in Atlanta and Boston, respectively, and evaluated how readily each class is likely to choose a decentralized water facility. Atlanta and Boston have some classes sharing similar preferences for decentralized water systems, but the socioeconomic and personal characteristics of these classes in the two cities are different. We found that the early adoption of decentralized water facilities is positively related to neighbors' adoptions and pressure of water scarcity increases households' willingness to share a decentralized facility. The visualization of spatial distribution of the classes highlighted early demand of decentralized water facilities is likely to emerge in low-property-value communities, which creates a unique opportunity for introducing decentralized water facilities during water infrastructure renovations. Our study provides a framework through citizen engagement to understand social demand and to inform the promotion of decentralized water facilities.

Influences of water quality and climate on the water-energy nexus: A spatial comparison of two water systems.

As drinking water supply systems plan for sustainable management practices, impacts from future water quality and climate changes are a major concern. This study aims to understand the intraannual changes of energy consumption for water treatment, investigate the relative importance of water quality and climate indicators on energy consumption for water treatment, and predict the effects of climate change on the embodied energy of treated, potable water at two municipal drinking water systems located in the northeast and southeast US. To achieve this goal, a life cycle assessment was first performed to quantify the monthly energy consumption in the two drinking water systems. Regression and relative importance analyses were then performed between climate indicators, raw water quality indicators, and chemical and energy usages in the treatment processes to determine their correlations. These relationships were then used to project changes in embodied energy associated with the plants' processes, and the results were compared between the two regions. The projections of the southeastern US water plant were for an increase in energy demand resulted from an increase of treatment chemical usages. The northeastern US plant was projected to decrease its energy demand due to a reduced demand for heating the plant's infrastructure. The findings indicate that geographic location and treatment process may determine the way climate change affects drinking water systems.