The Chalk is the most important source of fresh water in Northwestern Europe; more than eight million cubic meters of water are pumped daily from the aquifer. This book reviews the origin, sedimentology, and hydraulic properties of this unique rock, as well as the chemical characteristics of the water it contains. Separate chapters cover the occurrence of groundwater in the Chalk in each of the six countries which share its resources. The factors influencing the flow of oil through the Chalk and its role as a hydrocarbon reservoir in the North Sea are treated in detail. The industrial chemicals, fertilizers, and pesticides that have been allowed to enter the Chalk, thereby threatening its use for water supply are also discussed, with an emphasis on the factors that influence the distribution of the aquifer pollutants. This book will be of interest to a wide range of professionals and students, including those in geology, hydrogeology, water engineering, civil engineering, geography, water administration, and environmental science.