This lecture covers the importance of treating organic micropollutants (OMPs) due to their negative impact on the environment, the emergence of OMP as a topic of concern, Swiss legislation regulating OMP treatment, and the financing of OMP removal installations. It discusses the ecological impact of OMP on wildlife and humans, the challenges in measuring low concentrations of OMP, and the need for advanced treatment units in wastewater plants. The lecture also explains the modifications made to Swiss legislation in 2016 to include OMP parameters and the financial aspects related to OMP treatment projects.