Water Service Providers are increasingly tasked with providing sustainable approaches and processes in their service delivery, as shown by SDG 6. This is one of the main challenges for the WASH sector as a whole (Carrard & Willetts, 2017), and thus a main area of work in foreign aid and development. As many WSP, particularly in developing countries, are still struggling to achieve adequate service levels, considerable amount of collaboration between WSP in developed and developing countries will take place over the coming decades, as is the case with the Dutch water utilities and their WaterWorX programme. It is then crucial to delve deeper into how different WSP conceive sustainability, how these multiple conceptions lead to unique framings and enactments of sustainability, and how this multiplicity of conceptions influences knowledge exchanges in North-South and South-South development projects.