Thomas ter Laak works as a senior researcher in Chemical Water Quality on the sources, monitoring, behaviour, presence, as well as modelling of (new) micropollutants in the water cycle. Over the last ten years Thomas has conducted research into several compounds, including pharmaceuticals and their transformation products. Since 2018 he has also joined colleagues in research into illicit drugs in sewage water (wastewater-based epidemiology). One day a week Thomas is associate professor at the University of Amsterdam (IBED), where he teaches and supervises research in the field of environmental chemistry. Moreover, Thomas is affiliated with Utrecht University as a guest lecturer, and also supervises research at Wageningen University & Research.