As a researcher on the Chemical Water Quality and Health team, Ton van Leerdam draws on thirty years of experience to secure the (chemical) quality of the watercycle and signal new chemical substances. In doing so he applies the newest analytical techniques in close collaboration with the KWR chemical laboratory. Currently, the most valuable aspect is wide chemical screening with high-resolution mass spectrometry, providing an image of the water quality that is as complete as possible. Developments in monitoring the chemical water quality are tracked by means of scientific literature, international networks and congresses. Furthermore, Ton is a project manager of water-related projects on the Top Consortium for Knowledge and Innovation (TKI) and a member of the KWR Works Council.