"What a pleasure this book is! If you teach introductory hydrogeology to students of any discipline, then this book, by Paul Younger, is the one to recommend to your students as precourse or supplementary reading. If they read it, you will not need to give any lectures explaining the context, concepts, or issues...Put it at the top of your courses’ reading lists!" (David Lerner Groundwater Protection and Restoration Group, University of Sheffield, Groundwater Vol. 45, No. 3 2007)