With the growing concern about groundwater resources both with respect to quantity and quality, the need for groundwater modelling tools is increasing. Although there are a number of excellent introductions to the concepts of groundwater flow and pollution transport, the student or practising engineer wishing to develop a model and do practical work on the computer finds that there is still a gap between the understanding of concepts and the ability to handle the actual computations. A great deal of groundwater modelling software for personal computers and microcomputers has appeared recently, but taking these models from the shelf and applying them without a background on their capabilities often leads to disappointment and frustration. This book provides the reader with all necessary details to start modelling on his own. It gives a comprehensive introduction to the major techniques currently used in the modelling of groundwater flow and pollutant transport in groundwater.