Hendrik M. Haitjema, Ph.D., is the Editor-in-Chief of Groundwater. He joined Indiana University in 1984 where he served as a professor at the School of Public and Environmental Affairs until August 2012. He taught, among others, groundwater flow modeling and applied mathematics. Haitjema has a specialization in groundwater hydrology. His research interests include both the development and application of mathematical models for regional groundwater flow systems, three-dimensional groundwater flow embedded in two-dimensional flow models (Dupuit-Forchheimer models), fresh and salt water interface flow, transit time distributions in watersheds, and the conjunctive modeling of surface water and groundwater flow.