Since the number of users per toilet may be not controllable in all contexts, we explored the impact of varying several other parameters that could be controlled. This analysis included varying the impact of the number of households per toilet (with an uncertain number of people in each household), as well as other parameters that were identified to be significant from the sensitivity analysis (Figure ). Pit latrine emptying fees number of households per toilet were found to influence user cost (Figure ), where lower emptying fees and a greater number of households per toilet yielded the lowest cost (i.e., 0.03 [0.02 -0.06] USD•cap -1 •d -1 without an emptying fee and six households per toilet). For GHG emissions from the mixed excreta scenario, latrine emptying period was set to representative ranges of short (0.25 -0.5 yr) and long (2.0 -2.5 yr) periods between emptying (Figure ). Frequent emptying generated an average of 30% less total GHG emissions compared to infrequent emptying over the range of households per toilet, while having a minor impact on total user cost. Thus, for the deployment of the Biogenic Refinery, frequent emptying would be preferred over infrequent, when possible. For the sourceseparated excreta, efficiencies of resource recovery (i.e., resin lifetime for ion exchange, adsorption density for ion exchange, and filter reuse for struvite precipitation) were found to directly influence costs and GHG emissions (Figure ). These results reveal specific parameters that need to be considered and evaluated for deployment to ensure the overall sustainability of the OP.