Advanced processed wastewater for different uses: constellations favouring future implementation of a multimodal water reuse concept

Advanced wastewater treatment is often used to produce one single water quality. In recent years, technologies have been developed that allow the production of different qualities that are fit for their purpose. These technology bundles are still not being marketed, and market requirements are unclear. Two constellations in West Basin, California and in Oman were analysed to shed light on the different constellations of actors, resource situations and institutions. The first led to the industrial reuse of several water qualities, while the second produced an application in holiday resorts, leisure and food production. A hypothetical solution was contrasted with an historical case. The analysis of the constellations showed that multi-sectoral investments and dependencies require strong cooperation arrangements and long-term agreements. Governmental institutions were revealed to be suitable for coordinating the process, especially during the initial phase, but also in view of security of supply. A (comparative) examination allows an initial, still provisional systematic overview of other constellations that favour systems with recycled water of different qualities. Further research is required to understand the welfare and distribution effects of multimodal water pricing policies and the feasibility of co-financing of agricultural irrigation and opportunities for more sustainable water reuse.