This book is the proceedings of the International Conference on Water Contamination Emergencies: Monitoring, Understanding, Acting held in October 2010. The fourth in a series of conference proceedings, this book develops themes from three previous, highly successful Water Contamination Emergencies conferences in addition to dealing specifically with four new principle themes: monitoring, understanding, acting and lessons learned. With contributions from leading scientists and experts in academia and industry it offers a truly international perspective on our ability to deal with water contamination emergencies. Emphasis is given to prevention, strategy and unusual emergency incident situations relating to drinking water. This book should appeal to public health professionals, water companies, regulators, risk and business continuity managers, emergency planners, local authorities, service and support providers, disaster recovery specialists, water security experts, water distribution modellers, and all experts involved in emergency planning and response.