While extensive research has been performed on many technological aspects of permeable reactive barriers and a number of contaminants have so far been successfully treated by PRB systems, long-term performance has not been extensively considered and little is known about the processes influencing long-term behaviour. This gap in our knowledge is all the more disadvantageous as design life has a decisive influence on the economic viability of PRBs. The book describes methods for evaluation and enhancement of the long-term performance of PRB systems, especially of those targeting heavy metals, specifically uranium, and organic contaminants by sorption and/or precipitation mechanisms. Major topics in the book are: - Selection and characterisation of suitable reactive materials - Characterisation of the relevant contaminant attenuation processes - Developing new contaminant-binding chemical compounds ("ligands") - Accelerated testing methods to assess the long-term performance of the attenuation mechanisms in PRBs - Evaluation of the influence of site characteristics on PRB performance - Monitoring of existing and new field installations - Coupling of electrokinetic techniques and PRB systems - Large-scale laboratory and field tests and their results It addresses the long-term performance of PRBs, an important feature of this novel remediation technology, systematically. It deals extensively with heavy metal removal, with special emphasis on uranium. A number of case studies, experiences with large-scale modelling and test site experiments provide insight into the practical application of the results. This volume will contribute to the science underpinning groundwater remediation, and this will result in the improvement of quality of life and health and safety.* A systematic approach to investigating the long-term performance of permeable reactive barriers* Development of new contaminant-binding chemical compounds ("ligands"), accelerated testing methods to assess the long-term performance, and efficiency enhancing electrokinetic techniques* Extensive data and information on a Hungarian uranium mining facility; once a carefully kept secret of the Soviet Union