This collection presents a timely collection of social scientific papers dealing with innovative sanitation issues and concepts, perceptions and decision-making support. It comprises a valuable resource for political scientists, environmental engineers and urban planners involved in the study, design and implementation of sanitation projects worldwide and whose work relates to meeting the ambitious Millennium Development Goal of halving, by 2015, the number of people without sustainable access to safe drinking water and basic sanitation. In developed countries the sanitation challenge is to initiate a transition from strongly centralized, water-based infrastructure regimes towards more sustainable, source-separation oriented, sanitation regimes. This calls for social scientific research and demonstration on different levels and scales, including concept development, institutional learning and governance building. In the developing world the sanitation challenge is to provide sanitation services to the poor and the very poor, without compromising on sustainability. New configurations employing the best practices of sanitation technology and management for rural and urban contexts are needed. The sanitation challenge in both worlds is to go beyond traditional dichotomies between small, appropriate and modern/advanced technologies and to develop rural and urban sanitation with a mix of scales, strategies, technologies, payment systems and decision-making structures, that better fit the physical and human systems for which they are designed. This volume is unique in its presentation of social scientific research findings from urban planners, sociologists, economists, political scientists and environmental engineers who are involved in international sanitation research and implementation. Theoretically the volume include insights from Science and Technology Studies, Environmental Sociology and Urban Studies. Its empiricalscope stretches from sanitation projects in Western Europe to Sub-Saharan Africa.