title: Assessing Location and Scale of Urban Nonpotable Water Reuse Systems for Life-Cycle Energy Consumption and Greenhouse Gas Emissions.
abstract: Nonpotable water reuse (NPR) is one option for conserving valuable freshwater resources. Decentralization can improve distribution system efficiency by locating treatment closer to the consumer; however, small treatment systems may have higher unit energy and greenhouse-gas (GHG) emissions. This research explored the trade-off between residential NPR systems using a life-cycle approach to analyze the energy use and GHG emissions. Decentralized and centralized NPR options are compared to identify where decentralized systems achieve environmental advantages over centralized reuse alternatives, and vice versa, over a range of scales and spatial and demographic conditions. For high-elevation areas far from the centralized treatment plant, decentralized NPR could lower energy use by 29% and GHG emissions by 28%, but in low-elevation areas close to the centralized treatment plant, decentralized reuse could be higher by up to 85% (energy) and 49% (GHG emissions) for the scales assessed (20-2000 m3/day). Direct GHG emissions from the treatment processes were found to be highly uncertain and variable and were not included in the analysis. The framework presented can be used as a planning support tool to reveal the environmental impacts of integrating decentralized NPR with existing centralized wastewater infrastructure and can be adapted to evaluate different treatment technology scales for reuse.
authors.forename: Olga
authors.identifier: 0000-0002-9801-144X
authors.initials: O
authors.lastname: Kavvada
authors.forename: Arpad
authors.initials: A
authors.lastname: Horvath
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: Stokes-Draut
authors.affiliation: ICF International , 620 Folsom St., Suite 200, San Francisco, California 94107, United States.
authors.forename: Thomas P
authors.initials: TP
authors.lastname: Hendrickson
authors.forename: William A
authors.initials: WA
authors.lastname: Eisenstein
authors.forename: Kara L
authors.initials: KL
authors.lastname: Nelson
mesh_terms: D004777:Environment; D017752:Greenhouse Effect; D008018:Life Cycle Stages; D062065:Wastewater; D014867:Water
chemical_list: D062065:Wastewater; D014867:Water