Environmental impacts were estimated from four sources: capital, energy, direct impacts from excreta, and operation and maintenance. This analysis focused on the life-cycle global warming potential (i.e., GHG emissions as kg-CO2 equivalents). Impacts were estimated from the system's construction materials and electricity demands using the ecoinvent v3.6 database 46 and the U.S. EPA's Tool for the Reduction and Assessment of Chemicals and Other Environmental Impacts, TRACI 2.1 v1.03 . Direct GHG emissions from excreta during treatment were estimated using assumptions related to typical excretion of carbon and nitrogen and treatment conditions. The total impacts of fecal sludge management were normalized to a per capita basis over the course of a year (i.e., kg CO2 eq•cap -1 •yr -1 ). Details on the modeling procedures for environmental analysis are described in the Supporting Information (Section S2).