As main contractor at Amsterdam Schiphol Airport, BAM Infra Energie & Water strives for optimal asset maintenance for each and every one of their assets. In order to achieve this, one of the components which needs to be improved are the amount of malfunctions of Schiphol’s sewage pumping stations. These are caused by all types of obstructions, but especially towels and wipes. So far, BAM’s technically oriented solutions have not shown sufficient improvement. This was the base for this graduation project, in which I took a designerly, human oriented approach into solving the obstructions. I have tried to solve the obstructions at the source: the passengers at the airport. The goal of this project is to design a behavioural intervention, to prevent passengers from flushing waste down the toilets in the first instance. After reviewing research done into behavioural change and toilet design, as well as an evaluation of the stakeholders involved, a user research was set up to identify the behaviour which causes the flushing of waste and the reasons behind this. This was done in the form of exploratory interviews among a population representative of the possible visitors passing by at the airport. With the initial research, five design directions were established as a basis for ideation: signage, waste bins, towel dispensers, removing opportunity and feedback. A myriad of solutions were combined into an initial concept proposal, to be refined into a final, two-part concept: 1. A design of a new, user friendly and hygiene oriented waste bin, to be implemented in the individual toilet cubicles. The availability and user oriented design needs to make throwing waste into the bin more attractive than flushing it. 2. A repositioning of the cleaning personnel, where they are more in the forefront in a host-like manner. This will establish a connection with the passengers to give them a feeling of responsibility over the cleanliness of the toilet area, as well as a feeling of being watched to ensure the passenger behaves better. Combining these two interventions should trigger the passenger enough to lower the amount of waste being flushed and eventually the number of obstructions in the pumps. To confirm whether this concept actually achieves the intended behavioural change, a second user test was performed, in which the user group gave their thoughts on the new situation with the help of a use scenario to help them imagine themselves in this situation. With the user evaluation, as well as in-depth interviews with the three main stakeholders, BAM, Schiphol and cleaning company Vebego, the concept was optimised for implementation. The concept and its implementation came together in the final strategy, which consists of a detailed plan for a six month pilot to evaluate the effects in real life and the possible definite implementation of the concept after that.