Water Loss Assessment in Distribution Networks


Book Description

Water utilities worldwide lose 128 billion cubic meters annually, causing annual monetary losses estimated at USD 40 billion. Most of these losses occur in developing countries (74%). This calls for rethinking the challenges facing water utilities in developing countries, foremost of which is the assessment of water losses in intermittent supply networks. Water loss assessment methods were originally developed in continuous supply systems, and their application in intermittently operated networks (in developing countries) is hindered by the widespread use of household water tanks and unauthorised consumption. This study provides an extensive review of existing methods and (software) tools for water loss assessment. In addition, several new methods were developed, which offer improved water loss assessment in intermittent supply. As the volume of water loss varies monthly and annually according to the amount of supplied water, this study proposes procedures to normalise the volume of water loss in order to enable water utilities to monitor and benchmark their performance on water loss management. The study also developed a novel method of estimating apparent losses using routine data of WWTP inflows, enabling future real-time monitoring of losses in networks. Different methods have also been suggested to estimate the unauthorised consumption in networks. This study found that minimum night flow analysis can still be applied in intermittent supply if an area of the network is supplied for several days. Furthermore, this study concluded that water meter performance is enhanced in intermittent supply conditions. However, continuous supply in the presence of float-valves significantly reduces the accuracy of water meters. Finally, this study provides guidance and highlights several knowledge gaps in order to improve the accuracy of water loss assessment in intermittent supply. Accurate assessment of water loss is a prerequisite for reliable leakage modelling and minimisation as well as planning for, and monitoring of water loss management in distribution networks.




Losses in Water Distribution Networks


Book Description

This is a best practice manual for addressing water losses in water distribution networks worldwide. Systems and methodologies are presented for improving water loss and leakage management in a range of networks, from systems with a well-developed infrastructure to those in developing countries where the network may need to be upgraded. The key feature of the manual is a diagnostic approach to develop a water loss strategy - using the appropriate tools to find the right solutions - which can be applied to any network. The methods of assessing the scale and volume of water loss are outlined, together with the procedures for setting up leakage monitoring and detection systems. As well as real losses (leakage) procedures for addressing apparent losses, by introducing regulatory and customer metering policies are explained. Suggestions are made for demand management and water conservation programmes, to complement the water loss strategy. Recommendations are made for training workshops and operation and maintenance programmes to ensure skills transfer and sustainability. The manual is illustrated throughout with case studies. Losses in Water Distribution Networks will appeal to a wide range of practitioners responsible for designing and managing a water loss strategy. These include consultants, operations managers, engineers, technicians and operational staff. It will also be a valuable reference for senior managers and decision makers, who may require an overview of the principles and procedures for controlling losses. The book will also be suitable as a source document for courses in Water Engineering, Resource Management and Environmental Management.




Water Loss Assessment in Distribution Networks


Book Description

Water utilities worldwide lose 128 billion cubic meters annually, causing annual monetary losses estimated at USD 40 billion. Most of these losses occur in developing countries (74%). This calls for rethinking the challenges facing water utilities in developing countries, foremost of which is the assessment of water losses in intermittent supply networks. Water loss assessment methods were originally developed in continuous supply systems, and their application in intermittently operated networks (in developing countries) is hindered by the widespread use of household water tanks and unauthorised consumption. This study provides an extensive review of existing methods and (software) tools for water loss assessment. In addition, several new methods were developed, which offer improved water loss assessment in intermittent supply. As the volume of water loss varies monthly and annually according to the amount of supplied water, this study proposes procedures to normalise the volume of water loss in order to enable water utilities to monitor and benchmark their performance on water loss management. The study also developed a novel method of estimating apparent losses using routine data of WWTP inflows, enabling future real-time monitoring of losses in networks. Different methods have also been suggested to estimate the unauthorised consumption in networks. This study found that minimum night flow analysis can still be applied in intermittent supply if an area of the network is supplied for several days. Furthermore, this study concluded that water meter performance is enhanced in intermittent supply conditions. However, continuous supply in the presence of float-valves significantly reduces the accuracy of water meters. Finally, this study provides guidance and highlights several knowledge gaps in order to improve the accuracy of water loss assessment in intermittent supply. Accurate assessment of water loss is a prerequisite for reliable leakage modelling and minimisation as well as planning for, and monitoring of water loss management in distribution networks.




Drinking Water Distribution Systems


Book Description

Protecting and maintaining water distributions systems is crucial to ensuring high quality drinking water. Distribution systems-consisting of pipes, pumps, valves, storage tanks, reservoirs, meters, fittings, and other hydraulic appurtenances-carry drinking water from a centralized treatment plant or well supplies to consumers' taps. Spanning almost 1 million miles in the United States, distribution systems represent the vast majority of physical infrastructure for water supplies, and thus constitute the primary management challenge from both an operational and public health standpoint. Recent data on waterborne disease outbreaks suggest that distribution systems remain a source of contamination that has yet to be fully addressed. This report evaluates approaches for risk characterization and recent data, and it identifies a variety of strategies that could be considered to reduce the risks posed by water-quality deteriorating events in distribution systems. Particular attention is given to backflow events via cross connections, the potential for contamination of the distribution system during construction and repair activities, maintenance of storage facilities, and the role of premise plumbing in public health risk. The report also identifies advances in detection, monitoring and modeling, analytical methods, and research and development opportunities that will enable the water supply industry to further reduce risks associated with drinking water distribution systems.




Urban Water Distribution Networks


Book Description

Urban Water Distribution Networks: Assessing Systems Vulnerabilities and Risks provides a methodology for a system-wide assessment of water distribution networks (WDN) based on component analysis, network topology and, most importantly, the effects of a network's past performance on its seismic and/or non-seismic reliability. Water distribution networks engineers and system designers face multiple operational issues in delivering safe and clean potable water to their customers. - Includes vulnerability assessment methods for water distribution pipes - Discusses topological aspects and their effects on network vulnerability - Explores analytical and numerical modeling methods for finding and analyzing systems vulnerabilities in water distribution networks - Features real world case studies of networks under continuous and intermittent water supply operations




Assessment of Treatment Plant Performance and Water Quality Data: A Guide for Students, Researchers and Practitioners


Book Description

This book presents the basic principles for evaluating water quality and treatment plant performance in a clear, innovative and didactic way, using a combined approach that involves the interpretation of monitoring data associated with (i) the basic processes that take place in water bodies and in water and wastewater treatment plants and (ii) data management and statistical calculations to allow a deep interpretation of the data. This book is problem-oriented and works from practice to theory, covering most of the information you will need, such as (a) obtaining flow data and working with the concept of loading, (b) organizing sampling programmes and measurements, (c) connecting laboratory analysis to data management, (e) using numerical and graphical methods for describing monitoring data (descriptive statistics), (f) understanding and reporting removal efficiencies, (g) recognizing symmetry and asymmetry in monitoring data (normal and log-normal distributions), (h) evaluating compliance with targets and regulatory standards for effluents and water bodies, (i) making comparisons with the monitoring data (tests of hypothesis), (j) understanding the relationship between monitoring variables (correlation and regression analysis), (k) making water and mass balances, (l) understanding the different loading rates applied to treatment units, (m) learning the principles of reaction kinetics and reactor hydraulics and (n) performing calibration and verification of models. The major concepts are illustrated by 92 fully worked-out examples, which are supported by 75 freely-downloadable Excel spreadsheets. Each chapter concludes with a checklist for your report. If you are a student, researcher or practitioner planning to use or already using treatment plant and water quality monitoring data, then this book is for you! 75 Excel spreadsheets are available to download.




The Issues and Challenges of Reducing Non-Revenue Water


Book Description

Improving the efficiency of water utilities and reducing water losses are becoming top priorities in Asia, with its often-limited water resources and rapidly increasing urban population. This publication provides an up-to-date introduction to the subject matter, highlights the complexity of managing non-revenue water (NRW), offers guidance on NRW assessment, and recommends appropriate performance indicators. It is, to a large extent, based on the work of the Water Loss Specialist Group of the International Water Association in the last decade, and is amply complemented by the authors' practical experiences in Asia and in other countries around the world.




Performance Indicators for Water Supply Services


Book Description

The IWA Performance Indicator System for water services is now recognized as a worldwide reference. Since it first appearance in 2000, the system has been widely quoted, adapted and used in a large number of projects both for internal performance assessment and metric benchmarking. Water professionals have benefited from a coherent and flexible system, with precise and detailed definitions that in many cases have become a standard. The system has proven to be adaptable and it has been used in very different contexts for diverse purposes. The Performance Indicators System can be used in any organization regardless of its size, nature (public, private, etc.) or degree of complexity and development. The third edition of Performance Indicators for Water Supply Services represents a further improvement of the original manual. It contains a reviewed and consolidated version of the indicators, resulting from the real needs of water companies worldwide that were expressed during the extensive field testing of the original system. The indicators now properly cover bulk distribution and the needs of developing countries, and all definitions have been thoroughly revised. The confidence grading scheme has been simplified and the procedure to assess the results- uncertainty has been significantly enhanced. In addition to the updated contents of the original edition, a large part of the manual is now devoted to the practical application of the system. Complete with simplified step-by-step implementation procedures and case studies, the manual provides guidelines on how to adapt the IWA concepts and indicators to specific contexts and objectives. This new edition of Performance Indicators for Water Supply Services is an invaluable reference source for all those concerned with managing the performance of the water supply industry, including those in the water utilities as well as regulators, policy-makers and financial agencies.




Leak Detection


Book Description

Ageing infrastructure and declining water resources are major concerns with a growing global population. Controlling water loss has therefore become a priority for water utilities around the world. In order to improve efficiencies, water utilities need to apply good practices in leak detection. Leak Detection: Technology and Implementation assists water utilities with the development and implementation of leak detection programs. Leak detection and repair is one of the components of controlling water loss. In addition, techniques are discussed within this book and relevant case studies are presented. This book provides useful and practical information on leakage issues.




Water and Wastewater Management


Book Description

This volume addresses the situation of water and wastewater management from a global angle, underpinned by selected case studies. Without doubt, water and wastewater management are among the greatest challenges of our century, and there is also no doubt that the challenges posed by climate change will become even greater. However, most efforts, especially in developing countries but also in the so-called developed countries, have been less than optimal or not optimal at all. In particular, there are still too many people who have to live without clean water and decent sanitation. Today, 2.2 billion people lack access to safely managed drinking water and wastewater, and 4.2 billion people lack safely managed sanitation services. The question, why this is so and why in many cases in developing countries, is discussed in this book among other urgent water and wastewater management issues. The publication of this book is the start of a book series that in more detail critically reviews, discusses, and analyzes the water and wastewater situation and management in different regions and countries worldwide.