Laurence CHERY was awarded a Ph.D. Thesis in hydrogeology at the Paris XI University (Laboratory of Hydrology and Isotope Geochemistry). She started her professional career in 1988 as hydrogeologist in private consulting firm in France. In 1990, she joined the Water division at BRGM (the French Geological Survey) as a research engineer, in charge of methodological studies as part of Public Service activities in the field of Water Quality. She is presently in charge of a national groundwater database project, ADES, the quality and quantity national database for groundwater. Her work includes the design of new projects for solving specific problems in water quality, database, monitoring networks, and fieldwork. The main subjects include hydrogeochemistry, water circulation, natural groundwater geochemical background, water origin and transfer time, using isotopic techniques. She published several public reports, 30 articles and a book on "Groundwater natural background in France". She has been the secretary of the French Chapter of IAH since 2001.Ghislain de MARSILY is Emeritus Professor at the University Pierre et Marie Curie, Paris VI. He was trained as a mining engineer, and initially worked in oil well drilling and dam construction, before going to teaching and research at the Paris School of Mines in Fontainebleau (1967-1987) and later at the University Paris VI, on quantitative hydrogeology, geostatistics, aquifer modelling, waste disposal and water management at the large catchment scale. He published several books, including the text book "Quantitative Hydrogeology" at Academic Press, NY, and about 150 articles. He is a member of the French Academy of Sciences and Foreign Associate of the US National Academy of Engineering.