The potential to increase consistency in approaches to assessment and management of water-related microbial hazards was tackled by an international group of experts concerned with drinking water, irrigation and wastewater use and recreational/bathing water. It included individuals with expertise in public health, epidemiology, risk assessment, risk management, standards and regulation, communication and economics. Subsequently, a series of reviews was progressively developed and refined, which addressed the principal issues of concern linking water and health to the establishment of implemenation of effective, affordable and efficient guidelines and standards. This book is based on these reviews, together with the discussions of the harmonized framework that was proposed to improve consistency between guidelines and the issues surrounding it. This book should prove useful to all those concerned with issues relating to microbial water quality and health, including environmental and public health scientists, water scientists, policy makers and regulators.