In 2007 the City of Berne decided to implement Integrated Water and Biomass Management in the construction of the new housing development “Stöckacker Süd”. Integrated Water and Biomass Management is a sustainable alternative to conventional sewage disposal, because the waste water is filtered and cleaned in a decentralised treatment facility for local on-site absorption into the ground. Together with the project partners, seecon worked on the fundamentals of the concept in the pre-project phase, and reviewed the feasibility of various waste water treatment systems. In the process, different system components were tested for their operational suitability and underwent a sustainability assessment.