Life-Cycle Perspective on Residential Water Conservation Strategies

Abstract

Motivated by the desire to understand the impact of water supply systems on the environment, a life cycle-based hybrid methodology is used to assess the performance of two conservation scenarios, water efficiency, and rainwater harvesting, relative to the base case. The analysis carried out for the City of Toronto's residential sector estimates the operational energy use and GHG emissions, and the embodied burdens associated with water-efficient devices and rainwater tanks. Hydraulic simulations, performed on a hypothetical network to expose the impact of demand peak factor on pressure distribution at nodes, revealed some of the rainwater scenario strengths such as hydraulic stress curtailment and capital investment postponement. While both strategies led to significant water savings, the associated energy expenditures and emissions varied with the selection of system boundaries. Nevertheless, both conservation strategies are worthwhile pursuing for rendering the existing water systems more sustainable.

Life cycle assessment of low impact development technologies combined with conventional centralized water systems for the City of Atlanta, Georgia

“…[1]. As population expands, such water supply systems cannot be sustained with limited water resources and that makes it impossible to reduce carbon emissions if fossil fuel-based energy is used [2,3]. In the US,~40 million people in 772 cities rely on combined sewer systems (CSS) [4] that transport domestic wastewater and stormwater runoff in a single pipeline network connected into wastewater treatment plants.…”

Life cycle based evaluation of harvested rainwater use in toilets and for irrigation

“…The cost of implementing rainwater harvesting systems has also been studied by several authors (Zhang et al, 2009;Chiu et al, 2009;Rahman et al, 2010;Anand and Apul, 2010;Tam et al, 2010;Yuan et al, 2003;Liaw and Tsai, 2004;Ghisi and Mengotti de Oliveira, 2007;Ghisi et al, 2009;Liang and Van Dijk, 2011;Farreny et al, 2011;Morales-Pinz on et al, 2012;Walsh et al, 2014;Ghisi et al, 2014). Similarly, many authors studied the energy and greenhouse gas implications of rainwater harvesting systems Racoviceanu and Karney, 2010;Crettaz et al, 1999;Angrill et al, 2012;Gardner and Vieritz, 2010;Proenca et al, 2011;Morales-Pinz on et al, 2012;Vargas-Parra et al, 2013;Ghimire et al, 2014;Vieira et al, 2014). Yet, there still remain some knowledge gaps especially in modeling and using environmental criteria to assess rainwater harvesting systems (Angrill et al, 2012).…”

Integrated Assessment of Water Conservation Practices For Sustainable Management Strategies

“…However, there are only a few studies that have investigated the life cycle impacts of efficient technologies (Anand and Apul, 2011), especially for appliances with reduced water demands. Water efficiency conservation scenario is worthwhile for rendering sustainable water system (Racoviceanu and Karney, 2010) especially when technology and efficiency improvements of appliances may contribute to lower impacts from the production stage (Bole, 2006).…”

“…As a result, energy demands for hot-waterintensive appliances account for significant fractions of total demand during the end-use phase (73% for cloth washer and 93% for showerhead) ( Figure 5.4). Consequently, reducing the consumption of hot water is expected to reduce the associated environmental impacts (Racoviceanu and Karney, 2010).…”