Kevin M. Hiscock is a Professor in the School of Environmental Sciences at the University of East Anglia, U.K. He has over 35 years’ experience in teaching and research in hydrogeology, with interdisciplinary interests in hydrochemistry, environmental isotopes and the impacts of land use and climate change on groundwater resources and nutrient fluxes at regional and global scales. Victor F. Bense is an Associate Professor in the Department of Environmental Sciences at Wageningen University and Research, The Netherlands. He has over 20 years’ experience in teaching and research in hydrogeology, with specialist interests in the impact of shallow fault zones in unconsolidated sediments on groundwater flow and the hydrogeology of cold regions under changing climate.