Author: J. Lee
Publisher: IWA Publishing
ISBN: 1843398435
Category : Science
Languages : en
Pages : 228
Book Description
For many years, cross-connections and backflow have been well understood. Programs to prevent unhealthy situations from happening have been in place for many years. However, a general and extensive study on their impacts, types of programs, incidents, and financial repercussions has not been conducted. Many computer models for steady state or quasi-steady state simulation exist, but applications for transient state simulation, especially demonstrating backflow incidents, have rarely been done.The first objective of this project was to assess the impacts, financial and otherwise, of cross-connections and cross-connection control in North American water supplies and to North American water purveyors. The project team also planned to create and use a computer model to simulate and demonstrate hydraulic changes in the transient state.Of the over 700 utilities surveyed, 91% were found to have a cross-connection control program. Survey data indicated 65% of cross-connections were indirect and 35% were direct. Sudden changes of water demands in piping networks can cause sub-atmospheric pressures within the systems resulting in backflow incidents. Systems with larger variances in ground elevations have the greater possibility of creating sub-atmospheric pressures as water demands in the systems change.Originally published by AwwaRF for its subscribers in 2003 This publication can also be purchased and downloaded via Pay Per View on Water Intelligence Online - click on the Pay Per View icon below
Impacts of Cross-Connections in North American Water Supplies
Author: J. Lee
Publisher: IWA Publishing
ISBN: 1843398435
Category : Science
Languages : en
Pages : 228
Book Description
For many years, cross-connections and backflow have been well understood. Programs to prevent unhealthy situations from happening have been in place for many years. However, a general and extensive study on their impacts, types of programs, incidents, and financial repercussions has not been conducted. Many computer models for steady state or quasi-steady state simulation exist, but applications for transient state simulation, especially demonstrating backflow incidents, have rarely been done.The first objective of this project was to assess the impacts, financial and otherwise, of cross-connections and cross-connection control in North American water supplies and to North American water purveyors. The project team also planned to create and use a computer model to simulate and demonstrate hydraulic changes in the transient state.Of the over 700 utilities surveyed, 91% were found to have a cross-connection control program. Survey data indicated 65% of cross-connections were indirect and 35% were direct. Sudden changes of water demands in piping networks can cause sub-atmospheric pressures within the systems resulting in backflow incidents. Systems with larger variances in ground elevations have the greater possibility of creating sub-atmospheric pressures as water demands in the systems change.Originally published by AwwaRF for its subscribers in 2003 This publication can also be purchased and downloaded via Pay Per View on Water Intelligence Online - click on the Pay Per View icon below
Publisher: IWA Publishing
ISBN: 1843398435
Category : Science
Languages : en
Pages : 228
Book Description
For many years, cross-connections and backflow have been well understood. Programs to prevent unhealthy situations from happening have been in place for many years. However, a general and extensive study on their impacts, types of programs, incidents, and financial repercussions has not been conducted. Many computer models for steady state or quasi-steady state simulation exist, but applications for transient state simulation, especially demonstrating backflow incidents, have rarely been done.The first objective of this project was to assess the impacts, financial and otherwise, of cross-connections and cross-connection control in North American water supplies and to North American water purveyors. The project team also planned to create and use a computer model to simulate and demonstrate hydraulic changes in the transient state.Of the over 700 utilities surveyed, 91% were found to have a cross-connection control program. Survey data indicated 65% of cross-connections were indirect and 35% were direct. Sudden changes of water demands in piping networks can cause sub-atmospheric pressures within the systems resulting in backflow incidents. Systems with larger variances in ground elevations have the greater possibility of creating sub-atmospheric pressures as water demands in the systems change.Originally published by AwwaRF for its subscribers in 2003 This publication can also be purchased and downloaded via Pay Per View on Water Intelligence Online - click on the Pay Per View icon below
Drinking Water Distribution Systems
Author: National Research Council
Publisher: National Academies Press
ISBN: 0309133955
Category : Science
Languages : en
Pages : 404
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.
Publisher: National Academies Press
ISBN: 0309133955
Category : Science
Languages : en
Pages : 404
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.
Development of Distribution System Water Quality Optimization Plans
Author: Melinda J. Friedman
Publisher: American Water Works Association
ISBN: 1583213880
Category : Water
Languages : en
Pages : 256
Book Description
CD-ROM contains chapter 4 and appendices A & B.
Publisher: American Water Works Association
ISBN: 1583213880
Category : Water
Languages : en
Pages : 256
Book Description
CD-ROM contains chapter 4 and appendices A & B.
Susceptibility of Distribution Systems to Negative Pressure Transients
Author: Kala K. Fleming
Publisher: American Water Works Association
ISBN: 1583215115
Category : Water
Languages : en
Pages : 140
Book Description
Low or negative pressure transients (also called surge or water hammer) create temporary opportunities for external chemical and microbial contaminants at higher pressure to enter the water distribution system, creating potential health hazard and potential weakening of distribution pipes, leading to failure. This study investigates how such events as power outages, pump shutdowns, valve operations, main flushing, firefighting, and main breaks can create significant rapid, temporary drops in system pressure. The report offers useful recommendations for using surge models to optimally locate pressure monitors and to minimize the occurrence and impact from low- and negative-pressure transients.
Publisher: American Water Works Association
ISBN: 1583215115
Category : Water
Languages : en
Pages : 140
Book Description
Low or negative pressure transients (also called surge or water hammer) create temporary opportunities for external chemical and microbial contaminants at higher pressure to enter the water distribution system, creating potential health hazard and potential weakening of distribution pipes, leading to failure. This study investigates how such events as power outages, pump shutdowns, valve operations, main flushing, firefighting, and main breaks can create significant rapid, temporary drops in system pressure. The report offers useful recommendations for using surge models to optimally locate pressure monitors and to minimize the occurrence and impact from low- and negative-pressure transients.
Application of HACCP for Distribution System Protection
Author: Kathy Martel
Publisher: American Water Works Association
ISBN: 1583214828
Category : Science
Languages : en
Pages : 172
Book Description
OBJECTIVES: The purpose of this project was to evaluate the application of the Hazard Analysis Critical Control Point (HACCP) system, a risk management tool, to better protect water quality in distribution systems. BACKGROUND: HACCP was first conceived in 1959 by the Pillsbury Company to improve food safety for NASA & rsquo;s manned space missions. Since the 1980s, HACCP has been widely adopted by the food and beverage industry worldwide, where it forms an important part of their food safety plans. Since the mid-1990s, HACCP has been applied by a number of individual drinking water systems and has been incorporated into many drinking water regulatory requirements and guidelines around the globe. HIGHLIGHTS: Project pilot studies illustrated that HACCP can be applied to water distribution systems, but time and resource requirements were greater than anticipated. Project case studies showed that most utilities that achieved HACCP certification had first implemented ISO 9001 and ISO 14001 or similar systems to gain management control of people and processes. The case study utilities operated one integrated management system including the ISO systems as well as HACCP to avoid duplication of tasks, reduce staff time and costs, and improve process integration. All case study utilities believed that, overall, the benefits of the HACCP system outweighed the costs.
Publisher: American Water Works Association
ISBN: 1583214828
Category : Science
Languages : en
Pages : 172
Book Description
OBJECTIVES: The purpose of this project was to evaluate the application of the Hazard Analysis Critical Control Point (HACCP) system, a risk management tool, to better protect water quality in distribution systems. BACKGROUND: HACCP was first conceived in 1959 by the Pillsbury Company to improve food safety for NASA & rsquo;s manned space missions. Since the 1980s, HACCP has been widely adopted by the food and beverage industry worldwide, where it forms an important part of their food safety plans. Since the mid-1990s, HACCP has been applied by a number of individual drinking water systems and has been incorporated into many drinking water regulatory requirements and guidelines around the globe. HIGHLIGHTS: Project pilot studies illustrated that HACCP can be applied to water distribution systems, but time and resource requirements were greater than anticipated. Project case studies showed that most utilities that achieved HACCP certification had first implemented ISO 9001 and ISO 14001 or similar systems to gain management control of people and processes. The case study utilities operated one integrated management system including the ISO systems as well as HACCP to avoid duplication of tasks, reduce staff time and costs, and improve process integration. All case study utilities believed that, overall, the benefits of the HACCP system outweighed the costs.
Global Issues in Water, Sanitation, and Health
Author: Institute of Medicine
Publisher: National Academies Press
ISBN: 0309138728
Category : Medical
Languages : en
Pages : 328
Book Description
As the human population grows-tripling in the past century while, simultaneously, quadrupling its demand for water-Earth's finite freshwater supplies are increasingly strained, and also increasingly contaminated by domestic, agricultural, and industrial wastes. Today, approximately one-third of the world's population lives in areas with scarce water resources. Nearly one billion people currently lack access to an adequate water supply, and more than twice as many lack access to basic sanitation services. It is projected that by 2025 water scarcity will affect nearly two-thirds of all people on the planet. Recognizing that water availability, water quality, and sanitation are fundamental issues underlying infectious disease emergence and spread, the Institute of Medicine held a two-day public workshop, summarized in this volume. Through invited presentations and discussions, participants explored global and local connections between water, sanitation, and health; the spectrum of water-related disease transmission processes as they inform intervention design; lessons learned from water-related disease outbreaks; vulnerabilities in water and sanitation infrastructure in both industrialized and developing countries; and opportunities to improve water and sanitation infrastructure so as to reduce the risk of water-related infectious disease.
Publisher: National Academies Press
ISBN: 0309138728
Category : Medical
Languages : en
Pages : 328
Book Description
As the human population grows-tripling in the past century while, simultaneously, quadrupling its demand for water-Earth's finite freshwater supplies are increasingly strained, and also increasingly contaminated by domestic, agricultural, and industrial wastes. Today, approximately one-third of the world's population lives in areas with scarce water resources. Nearly one billion people currently lack access to an adequate water supply, and more than twice as many lack access to basic sanitation services. It is projected that by 2025 water scarcity will affect nearly two-thirds of all people on the planet. Recognizing that water availability, water quality, and sanitation are fundamental issues underlying infectious disease emergence and spread, the Institute of Medicine held a two-day public workshop, summarized in this volume. Through invited presentations and discussions, participants explored global and local connections between water, sanitation, and health; the spectrum of water-related disease transmission processes as they inform intervention design; lessons learned from water-related disease outbreaks; vulnerabilities in water and sanitation infrastructure in both industrialized and developing countries; and opportunities to improve water and sanitation infrastructure so as to reduce the risk of water-related infectious disease.
Impacts of Cross-connections in North American Water Supplies
Author:
Publisher:
ISBN:
Category : Cross-connections (Plumbing)
Languages : en
Pages : 209
Book Description
Publisher:
ISBN:
Category : Cross-connections (Plumbing)
Languages : en
Pages : 209
Book Description
Reviews of Environmental Contamination and Toxicology 192
Author: George Ware
Publisher: Springer Science & Business Media
ISBN: 0387717242
Category : Science
Languages : en
Pages : 212
Book Description
This book publishes detailed scientific review articles on all aspects of environmental contamination and associated toxicological consequences. The book will facilitate the task of accessing and interpreting cogent scientific data. It is likely to be of interest to researchers, resource managers, and policy administrators.
Publisher: Springer Science & Business Media
ISBN: 0387717242
Category : Science
Languages : en
Pages : 212
Book Description
This book publishes detailed scientific review articles on all aspects of environmental contamination and associated toxicological consequences. The book will facilitate the task of accessing and interpreting cogent scientific data. It is likely to be of interest to researchers, resource managers, and policy administrators.
Contaminated Water Supplies at Camp Lejeune
Author: National Research Council
Publisher: National Academies Press
ISBN: 0309136997
Category : Medical
Languages : en
Pages : 338
Book Description
In the early 1980s, two water-supply systems on the Marine Corps Base Camp Lejeune in North Carolina were found to be contaminated with the industrial solvents trichloroethylene (TCE) and perchloroethylene (PCE). The water systems were supplied by the Tarawa Terrace and Hadnot Point watertreatment plants, which served enlisted-family housing, barracks for unmarried service personnel, base administrative offices, schools, and recreational areas. The Hadnot Point water system also served the base hospital and an industrial area and supplied water to housing on the Holcomb Boulevard water system (full-time until 1972 and periodically thereafter). This book examines what is known about the contamination of the water supplies at Camp Lejeune and whether the contamination can be linked to any adverse health outcomes in former residents and workers at the base.
Publisher: National Academies Press
ISBN: 0309136997
Category : Medical
Languages : en
Pages : 338
Book Description
In the early 1980s, two water-supply systems on the Marine Corps Base Camp Lejeune in North Carolina were found to be contaminated with the industrial solvents trichloroethylene (TCE) and perchloroethylene (PCE). The water systems were supplied by the Tarawa Terrace and Hadnot Point watertreatment plants, which served enlisted-family housing, barracks for unmarried service personnel, base administrative offices, schools, and recreational areas. The Hadnot Point water system also served the base hospital and an industrial area and supplied water to housing on the Holcomb Boulevard water system (full-time until 1972 and periodically thereafter). This book examines what is known about the contamination of the water supplies at Camp Lejeune and whether the contamination can be linked to any adverse health outcomes in former residents and workers at the base.
Impact of Wet-Pipe Fire Sprinkler Systems on Drinking Water Quality
Author: Steven J. Duranceau
Publisher: American Water Works Association
ISBN: 0898679435
Category : Backsiphonage (Plumbing)
Languages : en
Pages : 426
Book Description
Publisher: American Water Works Association
ISBN: 0898679435
Category : Backsiphonage (Plumbing)
Languages : en
Pages : 426
Book Description