scholarly journals Effects of leakage points on intrusion volume in a simulated water distribution system

2019 ◽  
Vol 20 (1) ◽  
pp. 251-258
Author(s):  
Yu Shao ◽  
Shipeng Chu ◽  
Chenkai Dang ◽  
Tingchao Yu
Keyword(s):  
Health Risks ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Discharge Coefficient ◽  
Water Distribution System ◽  
Pilot Scale ◽  
Orifice Diameter ◽  
Urban Water ◽  
Public Health Risks

Abstract Contamination can intrude into urban water distribution systems through pipe leakage orifices or other deficiencies, which can create public health risks. Intrusion volume is a significant indicator of health risks when a pollution incident occurs. A pilot-scale platform was constructed to simulate the contamination intrusion through leakage holes caused by low or negative pressure events. The intrusion device was improved from the author's previous study by substituting the replaceable pipes in the main pipe for the side connecting pipe. Comparison between the two intrusion devices demonstrated that the intrusion device with the side connecting pipe may underestimate the intrusion volume. The orifice diameter range is extended to be 3–19.0 mm to analyze the effects of leakage sizes on the intrusion volume. The results show that the intrusion volume first increased and then decreased with increase of the orifice diameter. The calculated intrusion volume by the orifice discharge equation using the measured discharge coefficient is slightly different from the measured intrusion volume.

scholarly journals A Head Formulation for the Steady-State Analysis of Water Distribution Systems Using an Explicit and Exact Expression of the Colebrook–White Equation

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1163
Author(s):  
Mengning Qiu ◽  
Avi Ostfeld
Keyword(s):  
Steady State ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Solution Method ◽  
Water Distribution System ◽  
Academic Research ◽  
Exact Expression ◽  
Contamination Source

Steady-state demand-driven water distribution system (WDS) solution is the bedrock for much research conducted in the field related to WDSs. WDSs are modeled using the Darcy–Weisbach equation with the Swamee–Jain equation. However, the Swamee–Jain equation approximates the Colebrook–White equation, errors of which are within 1% for ϵ/D∈[10−6,10−2] and Re∈[5000,108]. A formulation is presented for the solution of WDSs using the Colebrook–White equation. The correctness and efficacy of the head formulation have been demonstrated by applying it to six WDSs with the number of pipes ranges from 454 to 157,044 and the number of nodes ranges from 443 to 150,630. The addition of a physically and fundamentally more accurate WDS solution method can improve the quality of the results achieved in both academic research and industrial application, such as contamination source identification, water hammer analysis, WDS network calibration, sensor placement, and least-cost design and operation of WDSs.

scholarly journals Mercury Speciation in the Water Distribution System of Skiathos Island, Greece

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 668
Author(s):  
Alexandra Spyropoulou ◽  
Yannis G. Lazarou ◽  
Chrysi Laspidou
Keyword(s):  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Tap Water ◽  
World Health Organisation ◽  
World Health ◽  
Urban Water ◽  
Groundwater Salinization ◽  
The World ◽  
Standard Set

In recent years, mercury (Hg) concentration that exceeds the Maximum Contaminant Level Standard set by the World Health Organisation for drinking water has been detected in the groundwater of Skiathos Island in Greece. The island single source of urban water is groundwater; as a result, tap water has been characterised as unsafe for drinking and people rely on bottled water for their everyday needs. The origin and speciation of Hg in the aquifer is investigated with the use of the Pourbaix diagram, while the possible correlation with groundwater salinization due to seawater intrusion is examined.

scholarly journals Optimal reconstruction of historical water supply to a distribution system: B. Applications

2004 ◽  
Vol 2 (3) ◽  
pp. 137-156 ◽  
Author(s):  
M. M. Aral ◽  
J. Guan ◽  
M. L. Maslia ◽  
J. B. Sautner ◽  
R. E. Gillig ◽  
...  
Keyword(s):  
New Jersey ◽  
Water Supply ◽  
Epidemiological Study ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Levels ◽  
Sensitivity Analyses ◽  
Toxic Substances

In a recently completed case-control epidemiological study, the New Jersey Department of Health and Senior Services (NJDHSS) with support from the Agency for Toxic Substances and Disease Registry (ATSDR) documented an association between prenatal exposure to a specific contaminated community water source and leukaemia in female children. An important and necessary step in the epidemiological study was the reconstruction of the historical water supply strategy of the water distribution system serving the Dover Township area, New Jersey. The sensitivity of solutions to: (1) pressure and pattern factor constraints, (2) allowable operational extremes of water levels in the storage tanks, and (3) the non-uniqueness of the water supply solution are analysed in detail. The computational results show that the proposed approach yields satisfactory results for the complete set of monthly simulations and sensitivity analyses, providing a consistent approach for identifying the historical water supply strategy of the water distribution system. Sensitivity analyses indicated that the alternative strategy obtained from the revised objective function and the variation of constraints did not yield significantly different water supply characteristics. The overall analysis demonstrates that the progressive optimality genetic algorithm (POGA) developed to solve the optimization problem is an effective and efficient algorithm for the reconstruction of water supply strategies in water distribution systems.

scholarly journals Biofilms from a Brazilian water distribution system include filamentous fungi

2013 ◽  
Vol 59 (3) ◽  
pp. 183-188 ◽  
Author(s):  
V.M. Siqueira ◽  
H.M.B. Oliveira ◽  
C. Santos ◽  
R.R.M. Paterson ◽  
N.B. Gusmão ◽  
...  
Keyword(s):  
Filamentous Fungi ◽  
Distribution System ◽  
Fluorescent In Situ Hybridization ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Sampling Device ◽  
Calcofluor White

Filamentous fungi in drinking water can block water pipes, can cause organoleptic biodeterioration, and are a source of pathogens. There are increasing reports of the involvement of the organisms in biofilms. This present study describes a sampling device that can be inserted directly into pipes within water distribution systems, allowing biofilm formation in situ. Calcofluor White M2R staining and fluorescent in situ hybridization with morphological analyses using epifluorescent microscopy were used to analyse biofilms for filamentous fungi, permitting direct observation of the fungi. DAPI (4′,6-diamidino-2-phenylindole) was applied to detect bacteria. Filamentous fungi were detected in biofilms after 6 months on coupons exposed to raw water, decanted water and at the entrance of the water distribution system. Algae, yeast, and bacteria were also observed. The role of filamentous fungi requires further investigations.

scholarly journals Management of water distribution systems in PDA conditions using isolation valves: case studies of real networks

2019 ◽  
Vol 22 (4) ◽  
pp. 681-690 ◽  
Author(s):  
A. Fiorini Morosini ◽  
O. Caruso ◽  
P. Veltri
Keyword(s):  
Case Studies ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Network ◽  
Optimal Number ◽  
System Management ◽  
System Control

Abstract The current paper reports on a case study investigating water distribution system management in emergency conditions when it is necessary to seal off a zone with isolation valves to allow repair. In these conditions, the pressure-driven analysis (PDA) is considered to be the most efficient approach for the analysis of a water distribution network (WDN), as it takes into account whether the head in a node is adequate to ensure service. The topics of this paper are innovative because, until now, previous approaches were based on the analysis of the network behaviour in normal conditions. In emergency conditions, it is possible to measure the reliable functioning of the system by defining an objective function (OF) that helps to choose the optimal number of additional valves in order to obtain adequate system control. The OF takes into account the new network topology by excluding the zone where the broken pipe is located. The results show that the solution did not improve significantly when the number of valves reached a threshold. The procedure applied to other real case studies seems to confirm the efficiency of the methodology even if further examination of other cases in different conditions is necessary.

scholarly journals Ranking Approach to Scheduling Repairs of a Water Distribution System for the Post-Disaster Response and Restoration Service

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1591 ◽  
Author(s):  
Bałut ◽  
Brodziak ◽  
Bylka ◽  
Zakrzewski
Keyword(s):  
Distribution System ◽  
Disaster Response ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Preference Ranking ◽  
Task List ◽  
Sequencing Method ◽  
Post Disaster

: On the maintenance task list of each water distribution system (WDS) operator, determination of the order of undertaken repairs seems quite a typical task. Characteristics of damages, their localization, and other factors that influence repair sequencing have a sound impact on the execution of such tasks. In the case of the most complex cases where numerous failures of different types occur at the very same time (i.e., due to earthquakes), there is a long list of selection criteria that have to be analyzed to deliver an objectively logical schedule for repair teams. In this article, authors attempt to find out if it is possible to define pipe rankings in having obtained the best factors for defined objective functions (criteria), making it feasible to deliver judicious repair sequencing. For the purposes of this paper, a survey has been carried out. Its conclusions made it possible to propose a method to create rankings of pipes and evaluate them using a selected multicriteria decision method: preference ranking organization method for enrichment evaluation (PROMETHEE). The work was carried out for five different disaster scenarios that had been supplied by ‘The Battle of Post-Disaster Response and Restoration’ organization committee. Obtained results might be further used to finetune this sequencing method of undertaken repairs, while conclusions could be useful to model similar events in WDS when required. This article is an extended paper based on the conference preprint presented at the 1st International Water Distribution Systems Analysis (WDSA)/International Computing & Control for the Water Industry (CCWI) Joint Conference in July 23–25, 2018 in Kingston, Ontario, Canada.

scholarly journals Exergy Evaluation of a Water Distribution System

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6221
Author(s):  
Jedrzej Bylka ◽  
Tomasz Mróz
Keyword(s):  
Water Treatment ◽  
Energy Loss ◽  
Water Supply ◽  
Case Studies ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Supply System ◽  
Water Supply System

The water supply system is one of the most important elements in a city. Currently, many cities struggle with a water deficit problem. Water is a commonly available resource and constitutes the majority of land cover; however, its quality, in many cases, makes it impossible to use as drinking water. To treat and distribute water, it is necessary to supply a certain amount of energy to the system. An important goal of water utility operators is to assess the energy efficiency of the processes and components. Energy assessments are usually limited to the calculation of energy dissipation (sometimes called “energy loss”). From a physical point of view, the formulation of “energy loss” is incorrect; energy in water transport systems is not consumed but only transformed (dissipated) into other, less usable forms. In the water supply process, the quality of energy—exergy (ability to convert into another form)—is consumed; hence, a new evaluation approach is needed. The motivation for this study was the fact that there are no tools for exergy evaluation of water distribution systems. A model of the exergy balances for a water distribution system was proposed, which was tested for the selected case studies of a water supply system and a water treatment station. The tool developed allows us to identify the places with the highest exergy destructions. In the analysed case studies, the highest exergy destruction results from excess pressure (3939 kWh in a water supply system and 1082 kWh in a water treatment plant). The exergy analysis is more accurate for assessing the system compared to the commonly used energy-based methods. The result can be used for assessing and planning water supply system modernisation.

scholarly journals Whole-Genome Sequences of Four Strains Closely Related to Members of the Mycobacterium chelonae Group, Isolated from Biofilms in a Drinking Water Distribution System Simulator: TABLE 1 

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Vicente Gomez-Alvarez ◽  
Randy P. Revetta
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Draft Genome ◽  
Drinking Water Distribution System ◽  
Genome Sequences ◽  
Mycobacterium Chelonae ◽  
Drinking Water Distribution

We report here the draft genome sequences of four Mycobacterium chelonae strains from biofilms subjected to a “chlorine burn” in a chloraminated drinking water distribution system simulator. These opportunistic pathogens have been detected in hospital and municipal water distribution systems, in which biofilms have been recognized as an important factor for their persistence.

Risk Assessment Modeling for Water Distribution Systems in Mega Cities

2013 ◽  
Vol 353-356 ◽  
pp. 2957-2960
Author(s):  
Jia Sun ◽  
Guo Ping Yu
Keyword(s):  
Risk Assessment ◽  
Land Subsidence ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Systems ◽  
Assessment Model ◽  
Strategic Decision ◽  
Mega Cities

In study of a series of damages to water distribution systems caused by urban land subsidence, risk assessment modeling is necessary for risk management especially in Mega-cities. First of all, the Catastrophe Theory was employed to analyze the Catastrophe mechanism, and a function catastrophe simulation model was established accordingly to get the vulnerability index of water distribution system. Secondly, risk entropy model was used to analyze the risk of pipe network suffering the land subsidence with the disorder and uncertainty features according to risk theory. Finally, to get the risk index the water distribution system of Guangzhou city was taken to the risk assessment model utilizing the level of land subsidence identified by the dimensional analytical method. The results showed that the risk of land subsidence under the city water distribution system security upgrade is feasible to provide a risk assessment of the strategic decision-making model.

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