Malcolm J. Brandt

Twort's Water Supply, Seventh Edition, has been expanded to provide the latest tools and techniques to meet engineering challenges over dwindling natural resources. Approximately 1.1 billion people in rural and peri-urban communities of developing countries do not have access to safe drinking water. The mortality from diarrhea-related diseases amounts to 2.2 million people each year from the consumption of unsafe water. This update reflects the latest WHO, European, UK, and US standards, including the European Water Framework Directive. The book also includes an expansion of waste and sludge disposal, including energy and sustainability, and new chapters on intakes, chemical storage, handling, and sampling. Written for both professionals and students, this book is essential reading for anyone working in water engineering.

When water leaves a treatment works and travels through a distribution system, its quality, with respect to many chemical and biological parameters, will degrade. The quality of the delivered water will be largely influenced by: The quality of treated water supplied into the network The condition of distribution assets within the network The retention time within the network. The water industry has focused predominantly on the quality of treated water and the physical condition of distribution assets when improving the quality of water at the customer?s tap. However the quality of the water delivered is also affected by the time the water is retained in the different elements of the distribution network. Retention time is controlled both by the physical characteristics of the system and the operational regime. Physical characteristics such as pipe roughness may change throughout the life of the asset or be modified by rehabilitation. The aim of this research is to demonstrate that water quality within distribution networks can be managed effectively by controlling retention time and to develop practical and pragmatic methodologies for doing so.