This report, co-sponsored by the American Water Works Association's Research Foundation and Kiwa of the Netherlands, evaluates the impacts of fire flow requirements on distribution system design and water quality using hypothetical and actual case studies. The report also evaluates alternatives to m
Many water utilities deal with water quality problems in the distribution system due to low water usage. This study uncovers the many problems of low usage and reports on the variety of mitigation practices used by North American utilities. An included CD-ROM provides decision support software to help utilities systematically weigh the costs and benefits of a variety of best management practices (BMPs) for mitigating the water quality issues caused by low usage and thus cutting down on customer complaints and higher distribution costs.
Fire flows have a significant impact on the design and operation of a water distribution system. Transient pressure surges are initiated by the operation of a hydrant and by the development of an abnormal water demand for fire fighting. Fire flows can create additional localized stress on the distribution network and may induce undesirable areas of low pressures, which may be either transient or sustained in nature. Many factors contribute to the intensity of transient surges including the size and layout of the network, the location of the operating hydrant, the hydrant valve operation, the supply or delivery rate, the presence of multiple hydrant operations, the water carrying capacity of the network, and the pipeline material. The Insurance Services Office method provides a good estimate for fire flow rates and many agencies endorse this method. The role of computer simulation and optimization helps greatly to evaluate all aspects of a distribution system.
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.
This brand new manual was written because of the increased use of chloramine as a residual disinfectant in drinking water distribution systems and the ubiquitous presence of nitrifying bacteria in the environment. Chapters cover background information on the occurrence and microbiology of nitrification in various water environments and provide current practical approaches to nitrification prevention and response. This manual provides a compendium of the current state-of-the-art knowledge, however with quickly developing new advances in nitrification, more writings will be forthcoming. Each chapter can be read independently.
Special Offer: KWR Drinking Water Treatment Set - Buy all five books together and save a total £119! Discolouration in Drinking Water Systems analyses the particle-related processes involved in the generation of discolouration problems in the network. To this end, new measuring methods have been developed such as continuous monitoring of turbidity and particle count, the Resuspension Potential Method (RPM), and the Time Integrated Large Volume Sampler (TILVS). With these new methods the discolouration problem can be seen as related to loose deposits in the network. The incidental re-suspension of accumulated loose particles is the main cause of discolouration events in the network. The origin of the particles is mainly the treated drinking water, followed by processes in the network like post-flocculation, corrosion and leaching and biological growth and re-growth. Irrespective of the cause of the particles the accumulation to layers of loose deposits can initiate water quality problems. This book looks at how managing the accumulation is possible through controlling the velocity in the pipes and through removing the loose deposits through effective cleaning.
Encyclopedia of Environmental Health, Second Edition, Six Volume Set presents the newest release in this fundamental reference that updates and broadens the umbrella of environmental health, especially social and environmental health for its readers. There is ongoing revolution in governance, policies and intervention strategies aimed at evolving changes in health disparities, disease burden, trans-boundary transport and health hazards. This new edition reflects these realities, mapping new directions in the field that include how to minimize threats and develop new scientific paradigms that address emerging local, national and global environmental concerns. Represents a one-stop resource for scientifically reliable information on environmental health Fills a critical gap, with information on one of the most rapidly growing scientific fields of our time Provides comparative approaches to environmental health practice and research in different countries and regions of the world Covers issues behind specific questions and describes the best available scientific methods for environmental risk assessment
