The need for improved sanitation around the world is becoming a crisis, and the situation is particularly critical in urban and peri-urban areas in developing countries. Here the population is growing rapidly, and where sanitation is provided, the means to treat and dispose of waste safely is neglected, with huge environmental and public health consequences. Sanitation solutions are needed that are safe for the user and interlinked with other urban services which can treat waste as a resource. This book describes an attempt to create modern, multi-storey urban dwellings that incorporate ecological sanitation into their design, resulting in a clean living space, and deriving safe agricultural inputs from human organic waste. The book highlights the experience of implementing the Erdos Eco-Town Project in Inner Mongolia, China. This remains the largest urban project of urine-diversion dry toilets in the world, serving a population of approximately 3000 people in 4-5 storey apartment buildings. The multi-storey collection system also links to on-site grey water treatment, a composting centre, underground urine tanks, and the agricultural reuse of nutrients. The Challenges of Urban Ecological Sanitation describes the technical design, daily operation and maintenance, costs and benefits compared to conventional systems, as well as the challenges in achieving acceptability with users. It includes technical information and illustrations, but also stresses the institutional structure needed to support this system and discusses its long-term sustainability.The Challenges of Urban Ecological Sanitation should be read by engineers, policy makers, researchers and NGO staff working in the field of water supply and sanitation.