A conceptual index for benchmarking intermittent water supply in a water distribution system zone

Various challenges, such as limited freshwater resources, climate change impacts, rapid population growth, urbanisation and underinvestment in water supply infrastructure, have led to intermittent water supply (IWS) in potable water distribution systems. Earlier research has confirmed that IWS negatively impacts the consumers, the infrastructure and the water supply authorities. Water supply authorities need tools to help understand IWS and the associated implications. A new indexing framework involving the causes and impacts associated with IWS is presented in this paper. In addition, a novel approach allows for quantification of the severity of IWS based on knowledge of a few readily available inputs. The severity quantification is based on two ratios: the intermittency ratio is a temporal measurement, accounting for supply duration; the connection ratio describes spatial aspects, using the number of service connections affected. The indexing framework and quantification tool could lead to improved understanding of IWS and could assist water supply authorities faced with IWS to make informed decisions. Improved planning of remedial actions to mitigate or avoid risks associated with IWS is aided. The tools presented in this paper could be used as basis for future development of a key performance indicator.

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Hydraulic Performance Analysis and Modeling of Water Supply Distribution System of Addis Ababa Science and Technology University, Ethiopia

10.20944/preprints202002.0149.v1 ◽

2020 ◽

Author(s):

Chalchisa Milkecha ◽

Habtamu Itefa

Keyword(s):

Water Supply ◽

Water Demand ◽

Distribution System ◽

Distribution Systems ◽

Water Distribution ◽

Addis Ababa ◽

Science And Technology ◽

Hydraulic Performance ◽

Alternative Methods ◽

The University

This study was conducted generally by aiming assessment of the hydraulic performance of water distribution systems of Addis Ababa Science and Technology University (AASTU). In line with the main objective, this study addressed, (1) pinpointing problems of existing water supply versus demand deficit (2) evaluating the hydraulic performance of water distribution system using water GEMS and (3) recommended alternative methods for improving water demand scenarios. The University’s water supply distribution network layout was a looped system and the flow of water derived by both gravity and pressurized system. The gravity flow served for the academic and administrative staffs whereas the pressurized system of the network fed the students dormitories, cafeteria’s etc. The study revealed the existence of unmet minimum pressure requirement around the student dormitories which accounts 25.64% below the country’s building code standard during the peak hour consumption. The result of the water demand projection showed an increment of 2.5 liter per capita demand (LPCD) in every five years. Hence, first, the university’s water demand was projected and then hydraulic parameters such as; pressure, head loss and velocity were modeled for both the existing and the improved water supply distribution. The finding of the study was recommended to the university’s water supply project and institutional development offices for its future modification and rehabilitation works.

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Rehabilitation Planning of Water Distribution neTwork through a Reliability – Based Risk Assessment

10.20944/preprints201712.0120.v1 ◽

2017 ◽

Author(s):

Marianna D'Ercole ◽

Maurizio Righetti ◽

Gema Raspati ◽

Paolo Bertola ◽

Rita Maria Ugarelli

Keyword(s):

Water Supply ◽

Distribution System ◽

Water Distribution ◽

Climate Change Impacts ◽

Water Distribution Network ◽

Supply System ◽

Water Supply System ◽

Analysis Model ◽

Output Analysis ◽

Support Tool

The management of existing water distribution system (WDS) is challenged by ageing of infrastructure, population growth, increasing of urbanization, climate change impacts and environmental pollution. Therefore, there is a need for integrated solutions that support decision makers to plan today, while taking into account the effect of these factors in the mid and long term. The paper is part of a more comprehensive project, where advanced hydraulic analysis for WDS is coupled with a dynamic resources input-output analysis model. The proposed modeling solution can be used to optimize the performance of a water supply system while considering also the energy consumption and consequently the environmental impacts. Therefore, as a support tool in the management of a water supply system also in the intervention planning. Here a possible application is presented for rehabilitation/replacement planning while maximizing the network mechanical reliability and minimizing risk of unsupplied demand and pressure deficit, under given economic constraints.

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An Approach to Estimating Water Quality Changes in Water Distribution Systems Using Fault Tree Analysis

Resources ◽

10.3390/resources8040162 ◽

2019 ◽

Vol 8 (4) ◽

pp. 162 ◽

Cited By ~ 6

Author(s):

Barbara Tchórzewska-Cieślak ◽

Katarzyna Pietrucha-Urbanik ◽

Dorota Papciak

Keyword(s):

Water Supply ◽

Distribution System ◽

Distribution Systems ◽

Water Distribution ◽

Fault Tree ◽

Water Distribution Systems ◽

Fault Tree Analysis ◽

Quality Changes ◽

The Stability ◽

Water Treatment Station

Given that a consequence of a lack of stability of the water in a distribution system is increased susceptibility to secondary contamination and, hence, a threat to consumer health, in the work detailed here we assessed the risk of such a system experiencing quality changes relating to the biological and chemical stability of water intended for drinking. Utilizing real operational data from a water treatment station, the presented analysis of the stability was performed based on the fault tree method. If they are to protect their critical-status water supply infrastructure, water supply companies should redouble their efforts to distribute stable water free of potentially corrosive properties. To that end, suggestions are made on the safeguarding of water distribution systems, with a view to ensuring the safety of operation and the long-term durability of pipes.

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

Journal of Water and Health ◽

10.2166/wh.2004.0013 ◽

2004 ◽

Vol 2 (3) ◽

pp. 137-156 ◽

Cited By ~ 3

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.

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Burst Detection in Water Distribution Systems: The Issue of Dataset Collection

Applied Sciences ◽

10.3390/app10228219 ◽

2020 ◽

Vol 10 (22) ◽

pp. 8219

Author(s):

Andrea Menapace ◽

Ariele Zanfei ◽

Manuel Felicetti ◽

Diego Avesani ◽

Maurizio Righetti ◽

...

Keyword(s):

Water Supply ◽

Water Consumption ◽

Distribution System ◽

Smart Grids ◽

Distribution Systems ◽

Water Distribution ◽

Stochastic Modelling ◽

Water Supply Systems ◽

Consumption Data ◽

Supply Systems

Developing data-driven models for bursts detection is currently a demanding challenge for efficient and sustainable management of water supply systems. The main limit in the progress of these models lies in the large amount of accurate data required. The aim is to present a methodology for the generation of reliable data, which are fundamental to train anomaly detection models and set alarms. Thus, the results of the proposed methodology is to provide suitable water consumption data. The presented procedure consists of stochastic modelling of water request and hydraulic pipes bursts simulation to yield suitable synthetic time series of flow rates, for instance, inlet flows of district metered areas and small water supply systems. The water request is obtained through the superimposition of different components, such as the daily, the weekly, and the yearly trends jointly with a random normal distributed component based on the consumption mean and variance, and the number of users aggregation. The resulting request is implemented into the hydraulic model of the distribution system, also embedding background leaks and bursts using a pressure-driven approach with both concentrated and distributed demand schemes. This work seeks to close the gap in the field of synthetic generation of drinking water consumption data, by establishing a proper dedicated methodology that aims to support future water smart grids.

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Exergy Evaluation of a Water Distribution System

Energies ◽

10.3390/en13236221 ◽

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.

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Rehabilitation Planning of Water Distribution Network through a Reliability – Based Risk Assessment

10.20944/preprints201712.0120.v2 ◽

2018 ◽

Author(s):

Marianna D'Ercole ◽

Maurizio Righetti ◽

Gema Raspati ◽

Paolo Bertola ◽

Rita Maria Ugarelli

Keyword(s):

Water Supply ◽

Distribution System ◽

Water Distribution ◽

Climate Change Impacts ◽

Water Distribution Network ◽

Supply System ◽

Water Supply System ◽

Analysis Model ◽

Output Analysis ◽

Support Tool

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Proposed probabilistic models of pipe failure in water distribution system

MATEC Web of Conferences ◽

10.1051/matecconf/201819302002 ◽

2018 ◽

Vol 193 ◽

pp. 02002

Author(s):

Thi Minh Lanh Pham ◽

Hai Ha Pham ◽

Nguyen Anh Thu Do ◽

Dinh Hong Le

Keyword(s):

Water Supply ◽

Distribution System ◽

Distribution Systems ◽

Water Distribution ◽

Unit Length ◽

Water Distribution Systems ◽

Labor Cost ◽

Experimental Models ◽

Pipe Failure ◽

Tree Model

All pipes in water supply network are installed underground, so it is difficult to identify pipe failure location during the operation of a system. Prediction of the risk of pipe failure in the water distribution systems is necessary for preparation of reparations and displacement of a pipe network system. Based on the probability of pipe failure, it will be possible to save money and labor cost for water supply companies. Many studies have been conducted on this topic, some of which used experimental models, others used statistical models in which recently many authors used regression model, but almost all the models come up with calculating the pipe failure rate per unit length of pipe in a year. It is not a direct probability of pipe failure. This article reviews various methods to evaluate pipe failure in water distribution systems. Based on that, the authors proposed two models: Regression Logistic Model and Decision Tree Model that would support an effective decision making for detecting the pipe failure and proposing appropriate solutions.

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Leakage discharge separation from the total water supply flow in water distribution system by constrained independent component analysis (CICA)

Water Science & Technology Water Supply ◽

10.2166/ws.2015.169 ◽

2015 ◽

Vol 16 (3) ◽

pp. 611-619

Author(s):

Chengzhi Zheng ◽

Jinliang Gao ◽

Wenjie He

Keyword(s):

Independent Component Analysis ◽

Water Supply ◽

Distribution System ◽

Distribution Systems ◽

Water Distribution ◽

Component Analysis ◽

Independent Component ◽

Total Water ◽

Simulation Accuracy ◽

Constrained Independent Component Analysis

The blind source separation theory was introduced and the trend and amplitude (TAA) model was established in order to overcome the shortcomings of some traditional global leakage discharge analysis models in water distribution systems (WDS). The TAA model considers the leakage discharge as one part of the total water supply flow, consisting of constrained independent component analysis (CICA) model and amplitude solving model. In the CICA model, the CICA algorithm was chosen and two reference vectors were constructed, and then the trend of leakage discharge was obtained. In the amplitude solving model, the two-element coupled linear overdetermined equations were derived and the amplitude was calculated. The TAA model was optimized and verified based on the data from three kinds of WDS (the laboratory WDS, the emulational WDS and the actual WDS). The simulation accuracy of the TAA model was high enough when the total water supply flow was a non-Gaussian signal in the WDS with one entrance only; the TAA model can effectively avoid the complexity (and reflect the uncertainty) of the relationship between leakage discharge and pressure head. More importantly, the model has good transplant performance.

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Application of a water balance adapted to intermittent water supply and flat-rate tariffs without customer metering in Tiruvannamalai, India

Water Science & Technology Water Supply ◽

10.2166/ws.2017.121 ◽

2017 ◽

Vol 18 (1) ◽

pp. 347-356 ◽

Cited By ~ 1

Author(s):

Miran Mastaller ◽

Philipp Klingel

Keyword(s):

Water Balance ◽

Water Supply ◽

Distribution Systems ◽

Water Distribution ◽

Water Losses ◽

Water Utility ◽

Flat Rate ◽

Intermittent Water Supply ◽

Water Association ◽

The City

Abstract Establishing the water balance developed by the International Water Association (IWA) is a worldwide applied approach to determine and analyse water losses in water distribution systems (WDS). The water balance covers those parts of a WDS within the responsibility of the water utility. Water losses occurring ‘before’ a customer meter are at the expense of the utility, while water lost or wasted ‘after’ the meter is paid for by the customer. This applies to systems where customer metering is in place and/or consumption is charged according to the consumed volumes. However, many WDS in the world lack customer meters, are operated intermittently and apply flat-rate tariffs. In intermittent supplies, a considerable amount of water is lost or wasted within the private properties. The flat-rate tariff might not cover this amount or part of the amount. Thus, actual consumption and wastage should be separately quantified with respect to the utility's water reduction measures. Accepting the described conditions, the authors have developed an adaption of the IWA water balance and the methods to establish the balance. In this paper the application of the developed approach in an initially unmetered WDS with intermittent water supply in the city of Tiruvannamalai, India, is presented.

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