As part of the Priority Programme 546 run by the Deutsche Forschungsgemeinschaft on the subject of "Geochemical processes with long-term effects in anthropogenically influenced drainage and ground water", a number of geoscientists, chemists, physicists, microbiologists, engineers and mathematicians all collaborated. This book describes the various ideas, concepts and conclusions that resulted and that were used to develop a model for the reactive transport of materials in drainage and ground water.