Worldwide replicability of alternative water recovery technologies to close water loops in decentralised populations

Decentralised systems to recover alternative sources of water (wastewater, rainwater, and seawater) can reduce water scarcity in rural areas by closing water loops while improving the local economy. However, their implementation commonly faces difficulties owing to social, legislative, technical, and economic barriers that must be assessed in local contexts. In this study, the implementation of six decentralised solutions (DCS) that were previously tested to recover water and other products was evaluated at 26 replication sites worldwide. Small, isolated locations were considered for site selection. They generally have scarce water resources and/or inappropriate water sanitation systems, and a high dependency on external regions. A quantitative feasibility assessment methodology (QFAM) developed in a previous study was used to evaluate the potential implementation of the DCS by quantifying relevant data regarding social, legislative, technical, and economic factors collected from the sites. From the results obtained in the overall assessment, the sites could be divided into two main groups: European sites that showed many similarities, especially in terms of common legal frameworks ruled by EU directives, and non-European sites that showed higher variations in local specificities. Most EU replicability sites showed high feasibility scores; however, for non-European sites, the results were distributed between high and medium feasibility scores. High scores were significantly influenced by high social and legislative feasibility assessments obtained at most sites. However, a general lack of understanding of the specificities of decentralised systems in local authorities and administrations was detected, which can be a significant barrier. Technical and economic assessments sometimes showed medium or low scores owing to certain limitations in the production of some circular products and the lack of financial instruments at some sites to reduce the initial investment for the implementation of DCS.