The CRT Selection Opportunity Space. The previously described results related to sustainability performance, drivers of costs and emissions, and typology trends by context can be used by decision-makers to understand the impact of context on NSS system selection. Although the Biogenic Refinery outcompetes the CRTs in terms of costs and emissions in all countries evaluated, constraints within the implementation context could make a CRT a more feasible option over a large-scale Omni Processor. Because a single Biogenic Refinery serves a population of 10,000+ users, it is best suited for more urban populations with higher population densities. Implementation in smaller communities that do not meet its design capacity would greatly impact the daily per capita costs and annual GHG emissions. Additionally, the Biogenic Refinery requires an onsite daily operator as well as transportation of excreta to the centralized treatment location, which could be too labor intensive for smaller, more dispersed communities.