Water distribution systems

ASTM D2846 CPVC hot water distribution system ... 

Internal Corrosion of Water Distribution Systems, Cooperative Research Report, AWWA Research Foundation, Denver, Colorado, DVGW-Forschungsstelle, 1985. 

At present, chlorine dioxide is primarily used as a bleaching chemical in the pulp and paper industry. It is also used in large amounts by the textile industry, as well as for the aching of flour, fats, oils, and waxes. In treating drinking water, chlorine dioxide is used in this country for taste and odor control, decolorization, disinfection, provision of residual disinfectant in water distribution systems, and oxidation of iron, manganese, and organics. The principal use of chlorine dioxide in the United States is for the removal of taste and odor caused by phenolic compounds in raw water supplies. 

Presence or absence of separate-phase gasoline near the home Witter supply system used by the dwelling s occupants i.e.. are they using a well that taps into tlic contaminated aquifer, or are tliey on a municipal water distribution system ... 

Figure 9-100. Atmospheric spray tower, air flow aspirated by pressure-spray water distribution system. Usually applied in small sizes. Used by permission of Hensley, John C. (ed), Cooling Tower Funds.-menteUs, 2nd Ed. (1985), The Mariey Cooling Tower Co., a United Dominion Company.

Vacuum DAs are seldom used in boiler plant systems but are widely used in water distribution systems. They typically reduce the DO content of water to 0.25 to 0.50 cc/1 (0.36-0.72 ppm) oxygen. 

Filters should be inspected for loss of media and agglomerated or blinded media. Media support and water distribution systems should be checked for fouling and mechanical soundness. 

Any colony optimization (ACO) and swarm intelligence are forms of agent-based modeling inspired by colonies of social animals such as ants and bees [32]. ACO has become popular in engineering for optimal routing in water distribution systems [33, 34]. Particle swarm optimization has been successfully used to train ANNs, for instance, ANNs to predict river water levels [35], for parameter estimation, for example, in hydrology [36]. 

Maier HR, Simpson AR, Zecchin AC, Foong WK, Phang KY, Seah HY, Tan CL (2003) Ant colony optimization for design of water distribution systems. J Water Resour Plan Manage 129 200-209... 

Zecchin AC, Simpson AR, Maier HR, Nixon JB (2005) Parametric study for an ant algorithm applied to water distribution system optimization, IEEE Trans. Evol Comput 9 175-190... 

Turbidity, due to solid particles in suspension, is a parameter generally neglected. However, under water scarcity, it is very important to be controlled because it may restrict the use of water for irrigation. Solid particles may clog the water distribution systems as drippers or sprinklers. They may also affect the soil permeability. This is why in different countries in the Mediterranean region special devices for the removal of sediments especially are used when marginal waters are only available for irrigation. 

Respiratory Effects. One study suggested increased respiratory disorders (asthma, bronchitis, pneumonia) in children with chronic exposure to a solvent-contaminated water supply (Byers et al. 1988). Two municipal wells in eastern Woburn, Massachusetts, were found to contain several solvents including trichloroethylene (267 ppb) and tetrachloroethylene (21 ppb). The increased susceptibility to infection may be secondary to effects on the immune system. Accurate chemical-specific exposure levels for individuals could not be determined because the water distribution system was designed to use water from different wells at different rates and times. Other limitations of this study are described in Section 2.2.2.8. 

Since ice storage tanks are used in HVAC system, the performance should be evaluated from system point of view. If the water distribution system had poor performance, performance of tank would be worse than its design value. Furthermore, heat load characteristics of the building also have large relation to system performance. System performance will be different for the building that has peaky load comparing to the building with flat load. 

The following is a generic test procedure that may be used to perform a flow performance of fire water distribution systems. 

Primary-secondary chilled water distribution systems were developed to allow a constant flow through chillers, required by the chiller manufacturers, with variable flow for the load side of the system to improve efficiency. The main applications are in multibuilding systems or... 

To monitor the nitrate and nitrite levels in water treated with chlorine and ammonia, water samples must be obtained regularly from water distribution systems and plant process sites and taken to a laboratory for analysis. 

The project plan should encompass all aspects of a fire protection system, such as the underground fire water distribution system, fire pumps, aboveground water header, valving and standpipes, structural support, and detection and alarm systems. All work on the fire protection system must be coordinated with other work activities at the site or in the operating unit. The recommended installation practices for the different types of fire protection systems are covered in consensus standards, such as NFPA. The installation process is illustrated in Figure 9-1. 

Fire water distribution systems should be inspected and tested regularly to ensure water can be delivered to all locations as required. Table 10-3 summarized the inspection and tests for components in a fire water distribution system. 

Inspection, Testing, and Maintenance for Fire Water Distribution Systems... 

Niquette P, Servais P, Savoir R (2001) Bacterial dynamics in the drinking water distribution system of Brussels. Water Res 35(3) 675-682... 

Koskinen R, Ali-Vehmas T, Kampfer P et al (2000) Characterization of Sphingomonas isolates from Finnish and Swedish drinking water distribution systems. J Appl Microbiol 89(4) 687-696... 

Blanch AR, Galofre B, Lucena F et al (2007) Characterization of bacterial coliform occurrences in different zones of a drinking water distribution system. J Appl Microbiol 102(3) 711-721... 

The water distribution system in the city of Dayton, OH, uses Southdown concrete water mains to deliver water to its citizens. Routine sampling and testing of Dayton s water supply by the city s Department of Water consistently shows that the levels of metals are well below the Ohio EOA Community Drinking Water Standards, and that these levels have remained constant throughout a nine-year testing period from 1982 to 1990. Because metal leaching has not occurred, there is no reason for concern over the safety of Southdown concrete pipes to transport drinking water. 

Environmental Fate. Little experimental data on the resonance time and half-life of chlorine dioxide and chlorite (ions or salts) in the atmosphere are available. Additional information on the transport of chlorine dioxide in the atmosphere may be useful, considering that over 900,000 pounds are released annually to air (TRIOO 2002). Additional information about the mechanism of reformation of chlorine dioxide in water distribution systems from chlorite ion is needed (Hoehn et al. 1990). Additional information concerning the transport and partitioning of chlorite (ions or salts) is also needed. 

Although worries abound over contamination of the water supply, in reality, the task is quite difficult to accomplish. For example, a contaminant can be dumped into a reservoir, but studies show that the chemical does not mix throughout the entire body of water, even after many hours. There are multitudes of chemical and biological agents that can be used to contaminate the water supply, but all contaminants do not behave similarly. Not all contaminants are threats—some become unstable in water, while others require such large quantities to do harm that they could never be dumped without being noticed. Additionally, if a disinfectant residual is maintained in the water distribution system, that residual will react with the contaminant, and the populace will remain relatively safe. It will be extremely difficult for terrorists to successfully contaminate the water supply. 

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