Bas van der Grift is senior researcher in hydrogeochemistry. He has a solid scientific background in water quality and environmental geochemistry. His experience ranges from land use and pollution of the shallow soil and groundwater up to the assessment of the quality of deeper groundwater and quantitative assessments through advanced groundwater quality modelling. Bas’s primary research focuses on water chemistry to understand hydrologic and biogeochemical processes at scales ranging from mineral-water interfaces to water flow paths in watersheds and regional aquifers. Preferably, he combines field characterisation and assessment campaigns with modelling studies to reveal the hydrochemical functioning of groundwater systems. He applied his expertise internationally in countries in the Middle East, North America and Central and Eastern Europe. His expertise is frequently used for initial evaluations and second-opinions for critical conditions as well as policy support.