Hydrogeology PhD (Vrije Universiteit, Amsterdam, the Netherlands). Professor of Water Quality Management at Utrecht University (2011 to date) and expert researcher at TNO Geological Survey of the Netherlands (1991 to date). Specialised in environmental hydrology and geochemistry within the framework of sustainable management of soil and water resources. He performed studies for a wide variety of geographical settings and a broad range of environmental management issues, ranging from an acid crater lake in Indonesia to disposal of radioactive waste in the deep subsurface of the Netherlands. Many of his projects refer to the risks and impact of anthropogenic measures on groundwater and subsequent effects on drinking water and groundwater-dependent ecosystems. Preferably, he combines field campaigns with modelling studies. He contributed chapters to several text books among which “UNESCO Groundwater Studies” and “Sustainable Groundwater Resources in Africa” in addition to his peer-reviewed publications. As member of the former ministerial Dutch Technical Committee on Soil, he was involved in c. 100 ministerial advices during October 2007 – March 2016; he has been an expert in several cases for Dutch Courts of Justice, too.