Reliability Of Water Supply System Research Articles

Ключевые направления и мировые практики повышения эффективности и надежности водоснабжения

The article reviews modern research and practical developments in the field of increasing the efficiency and reliability of water supply systems. The analysis covers both the micro level, which includes optimizing the opera-tion of individual components of the system, and the macro level, related to the management and optimization of the water supply system as a whole. Particular attention is paid to improving the efficiency of pumping units, leaks and pressure losses management, as well as water treatment processes optimization. At the macro level, the article presents a review of strategies for the optimal distribution of water between water intakes, a study of the zones of water intakes influence on the hydraulic network, dynamic pressure planning and power consump-tion management of pumping stations. The importance of monitoring and diagnostics systems for increasing the reliability of water supply systems is emphasized. Key areas of research and current problems are identified, and promising approaches to improving the management of urban water supply systems are proposed

Effect of bubble volume on the sweeping velocity of air bubbles in horizontal pipelines in water supply system

Trapped air bubbles in pipelines significantly affect the safety and efficiency of water supply systems, potentially inducing water hammer and leading to pipeline explosions and interruptions. This study investigates the sweeping velocity of air bubbles in horizontal pipelines by analyzing the forces acting on a single air bubble and deriving a theoretical expression for calculating the sweeping velocity. Physical model experiments and numerical simulations are conducted to examine the variations in sweeping velocity with respect to bubble volume and dimensionless bubble volume. Results indicate that the sweeping velocity increases with bubble volume, and the diameter of the pipeline significantly affects the movement of air bubbles. These findings contribute to a better understanding of air bubble behavior in horizontal pipelines and can inform strategies for mitigating risks associated with trapped air bubbles, ultimately improving the safety and reliability of water supply systems.

Comparative Study on Strategies for the Division of Earthquake-Proof Strengthening Segments to Reinforce the Reliability of Water Supply Systems

It is very important to secure the sustainability of physical and non-physical social infrastructure facilities in the event of a disaster. The water supply network is particularly vulnerable to seismic damage, and so physical earthquake resistance is very necessary to adapt to or withstand disaster situations. This study evaluated various strategic methods to improve the reliability of water distribution network systems in the event of an earthquake disaster with a focus on structural earthquake-proofing methods for pipelines. For this purpose, three major flow-, diameter- and connection-hierarchy-based earthquake proofing strategies are proposed. We quantified the extent to which earthquake reliability improved after the strengthening of the earthquake-proofing of the pipeline segments, which had been divided based on the proposed strategies. The proposed methodology of dividing the pipeline segments for earthquake-proof strengthening was applied to the water supply system of the Republic of Korea and analyzed thereafter. As a result, it was confirmed that the associated costs and the extent of the improvement in the reliability of earthquake proofing for each strategy and scenario need to be precisely analyzed. Thus, it is necessary to execute strategic earthquake proofing of pipelines with medium size diameters and which occupy most of the length of a mainline, in order to simultaneously satisfy the reliability and cost efficiency of the relevant water supply. However, additional earthquake proofing for segments of a higher level of flowrate is required because a marked drop in overall reliability is caused if they are damaged. In addition, because the effect of an increase in reliability in comparison with the costs incurred is insignificant in the case of some low demand and small-diameter pipeline segments, it is reasonable to exclude earthquake resistance strategies for these sections. The proposed study results—determining the level of importance of each resistance method—can be utilized to make a combined plan for optimal earthquake-proofing strategies.

Service level indicators evaluation of water supply systems: water users’ perspective

ABSTRACT Service level of water supply systems (WSS) was assessed across in Ogun State, Southwest Nigeria. The WSS included: self-supply systems, communal water supply systems, and public water systems. Five service level indicators (access, quality, management, cost, and reliability) were assessed using structured questionnaires, targeting WSS users and owners in two categories: owners/resident users and non-resident users. Results show that owners/resident users restricted access of non-resident users to water assets, hence reducing adequate service level. Post-collection treatment was practiced by some users, using sodium hypochlorite solutions. Management and costs of WSS are borne by owners/resident users; costs borne by non-resident users is only from purchase of water. Reliability of WSS is hampered by geology and climatic seasonal variations as some WSS dried up during the off-rain season. Poor access to water has been identified as a major challenge facing non-resident users, amplified by limited coverage area of public water supply systems.

Efficient pathways to zero-carbon energy use by water supply utilities: an example from London, UK

Urban water utilities are increasing their use of energy-intensive technologies such as desalination and long-distanced pumped transfers. Under pressure to reduce their energy-related carbon emissions to zero, water utilities have devised a variety of energy management strategies, including the purchase of renewable energy and self-generation of electricity using locally installed renewables. These strategies will incur different costs for the utility, whilst some may have implications for the reliability of water supply systems. Yet the trade-offs between costs, water security and energy sustainability remain unexplored. Here, we present a regional scale analysis to test competing energy strategies, mapping pathways to zero carbon energy and water security. Results from a case-study of the London water system show a balanced approach that allows for some energy self-generation, using biogas, solar and wind, while also purchasing green energy credits from the electricity supply grid can best navigate this trade-off. Balanced investment plans can accommodate energy-intensive water supply techniques such as long-distance transfers, desalination and effluent reuse while meeting energy targets. By becoming energy generators and also adopting more flexible arrangements for energy use, water utilities could become significant players in energy markets.

Modeling and Optimization of the Drinking Water Supply Network—A System Case Study from the Czech Republic

In this study, we investigated the modelling and optimization of drinking water supply system reliability in the village of Zaben, Czech Republic. An in depth overview of the water supply network in the municipality, passport processing and accident and malfunction recording is provided based on data provided by the owner and operator of the water mains as well as the data collected by our own field survey. Using the data processed from accident and failure reports in addition to water main documentation, the water supply network in Zaben was evaluated according to the failure modes and effects analysis methods. Subsequently, individual water supply lines were classified based on their structural condition. In addition, a proposed plan for financing the reconstruction of the water supply mains in Zaben was created. As such, this study provides an overall assessment of the water supply network in Zaben alongside a proposed plan for the structural restoration of the water supply system, which accounts for the theoretical service life of the system and the financial resources of the owner.

Seismic Reliability Assessment of Water Supply Systems Considering Critical Paths

In general, studies of the seismic reliability of water supply systems through hydraulic analysis models fall into three categories: (1) model development through hydraulic analysis, (2) establishment of post-earthquake recovery strategies, and (3) robust design in preparation for earthquakes and the development of improvement techniques. In this study, with regard to the design of earthquake resistance techniques, which is the third category, a seismic reliability assessment was conducted that considers the water supply system, and a plan to maximize the seismic reliability was determined as a result of the analysis. The degree of improvement in seismic reliability was quantified for water supply systems with various sources and water supply routes via modeling of seismic protection for each water supply route. Korea’s A industrial water system, which has a history of large-scale earthquakes, was divided into nine paths, and the reliability of the water supply system and the cost of earthquake resistance were calculated and compared between the different paths. A water supply path consists of a combination of pipes of various sizes and lengths, and the amount of water to be supplied differs between paths. Quantifying the effect of the water supply system and the seismic reliability of a route is intended to provide a basic methodology for identifying the critical path that should be the target of seismic protection when money and resources available for construction are limited. This methodology was used to confirm that the reliability of the water supply, the demand for water, and the cost of earthquake resistance should be considered together to establish an earthquake resistance strategy for the critical path in a water supply system. We expect that the results of this study will be used to establish detailed strategies for preliminary reinforcement against earthquake damage based on critical paths rather than all or individual pipelines in a water supply network.

ENSURING COST-EFFECTIVE AND RELIABLE OPERATION OF AGRICULTURAL WATER SUPPLY SYSTEMS (AS IN THE CASE OF WATER SUPPLY SYSTEMS OF TARASIVKA VILLAGE IN KYIV REGION)

The current state of water supply in Ukraine was analyzed and the main problems that arise on the existing water supply systems, related to the lack of efficiency of both water treatment technologies and operation conditions of the water supply system structures, characterized by high energy consumption, excess pressure formation and accident rate increase were studied. It was specified that in agricultural water supply systems additional difficulties can arise due to significant fluctuations of water consumption during the day, therefore, there is a need for the study of the joint work of interacting structures, especially in the towerless schemes. It is shown that to solve the problems of reliable provision of consumers with the required water amounts, water pressures and water quality, is possible taking into account the requirements of economy, reliability and environmental safety, and to identify weaknesses and develop recommendations for ensuring the efficient operation of structures can be fulfilled by mathematical modeling and analysis of various possible variants of system operation. The issue of increasing the efficiency and reliability of agricultural supply systems was considered using the example of the water supply system in Tarasivka village of Kyiv region. The article deals with increasing the efficiency and reliability of agricultural water supply systems. The results of the study of water supply systems operation, based on the utilization of ground water in the village of Tarasivka, Kyiv region are given, which demonstrate that when pumping water from the well directly into the water supply network, excess damage energy for water lift occurs. The reliability of the water supply system, when pumping water from the well, was analyzed and the measures to ensure cost-effective and reliable operation of water supply structures while reducing the specific costs of electricity for supplying water to consumers and improving its quality were proposed.

Fuzzy Reliability-Vulnerability for Evaluation of Water Supply System Performance

The reliability of water supply system is a critical factor in the development and the ongoing capability to succeed in life and people's health. Determining of its, with high certainty, for performance of water supply system is developed to ensure the sustainability of system. Reliability (Re) plays a great role in evaluation of system sustainability. The probability approaches have been used to evaluate the reliability problems of systems. The probability approach is failed to address the problems of reliability evaluation that comes by subjectivity, human inputs and lack of history data. This research proposed two models; I) traditional model: fuzzy reliability measure suggested by Duckstein and Shresthaand then developed by El-Baroudy; and II) developed model: fuzzy reliability-vulnerability model. The two models implemented and evaluation of water supply system by using two hypothetical systems (G and H). System (G) consists of a single pump and System (H) consists of a two parallel pumps. Triangular and trapezoidal membership functions (MFs) are used to investigate of the reliability measure to the form of the membership function. The results agree with expectations that the reliability of parallel component system {ReH (0.53)} is higher than the reliability of single component system {ReG (0.47)}. Moreover, the result by using fuzzy set reduces the effect of subjectively in process of decision-making (DM). The fuzzy reliability vulnerability is able to handle different fuzzy representations and different operation environment of system

Operational dependability of water intake facilities

Operational dependability of water intake facilities means that all the elements provides execution of the specified functions for this intakes and water pre-treatment at operational level and in essential limits for any locality, town or industry. Questions about the reliability of water supply systems were taken and examined not only by Russian scientists (such as N. Abramov, L. Derushev, O.Primin, Y.Il’in, V. Makagonov, V. Malov) but foreign researches too (Howe Charles W., Smith Mark Griffin, Qi Yang, Sanchez-Torres G., Paul Jeffrey). The water intake facility is the first element in a water supply system, as a result it has to be very reliable. It influences on the common quality of the system.Some essential factors have been analyzed. Each of them could have affect on the water intake facility. So we should divide them into two main categories: natural and technical. The first one depends on the type of the water structure with using water intake facility, for example, rivers, water chanels or reservoirs. Natural factors include presence or absence of biological deposits, sludges or something else. But technical factors have such properties as durability, storage characteristics and probability of survival.It’s very important to say that dependability of water intake facilities could directly subject to probabilistic laws of happening any events, that could lead to element failure or breaking down of the whole system.Based on the ranging natural and technical factors the special tables were compiled. Now we can determine the most and the least service or repair availability of the water intake facility failure at some specified parameters. By the way, if we sum up all the values of influence natural and technical factors, we will find out which one of the water intake facility has depleted operational conditions. Besides, it is important to say that such technical factors as durability, storage characteristics and probability of survival have been described by the specific mathematical dependencies and in sum with natural factors they let us understand the whole picture of considered problem.

Improving of the quality and reliability of water supply systems on the basis of modern information and computing technologies

The article deals with the issues of increasing the reliability and quality of water supply systems operation on the basis of modern methods and software complexes for the analysis and development of hydraulic conditions. Against the backdrop of the analysis of the literature on the problem of reliability, the relevance and insufficiency of attention to maintaining the required level of reliability at the stage of water supply systems operation are revealed. The main factors that affect on operational reliability are considered. These factors are largely associated with the competent organization of operating conditions of water supply systems. A brief description of the «Angara-WS» computer program for solving the problems of analyzing and developing of hydraulic conditions, as well as the experience of its practical application, is given. A special feature of this complex is its universality, the possibility of multilevel representation of models, the execution of one-and multi-level calculations, integration into a common information space of the enterprise, automation of the processes of mode analysis, accumulation and analysis of damage statistics.

ON-LINE DRINKING WATER CONTAMINATION EVENT DETECTION METHODS

A task of water supply systems is to provide safe drinking water to every customer, which is a basic human need. Aging of water supply networks and increased precaution of terrorism risks led to re-evaluation of drinking water supply system reliability and vulnerability to accidental and intentional contamination. Contamination of drinking water can cause health, social, psychological and economic issues. During the last decade, early warning systems (EWS) were often used to ensure the safety of drinking water. EWS are driven by conventional sets of drinking water quality sensors, and the collected data are analyzed in real time. For detection of contamination events, numbers of algorithms have been developed. Most of the algorithms are based on statistical analysis or machine learning. The aim of this study was to compare existing methods and to identify the method, which is suitable for contamination detection in drinking water from non-compound specific sensors and requires relatively low computational resource. 
 A detailed review of 11 different algorithms was presented in the current study with the primary focus on detection probability. Cluster analysis in combination with Mahalanobis distances of feature vectors and Canonical correlation analysis (CCA) approach were selected as the most promising methods for application in a new generation of EWS to detect and classify possible contamination events and agents. While canonical correlation analysis method was the most accurate for detection of contamination events, an advantage of Mahalanobis distances was that it not only detects the contamination events but also could identify the type of contaminant. In this study, we conclude that CCA and Mahalanobis distance methods might be applied for detection of contamination events with relatively high and reliable precision.

Modelling Resilience of a Water Supply System under Climate Change and Population Growth Impacts

Climate change impacts and increased demand due to population growth are among the most common disruptions or pressures that can undermine the service potential of a water supply system. Consequently, the successful management of a water supply system depends on an in-depth understanding of the resilience of the system to such pressures. This study developed a robust modelling approach to assess the resilience of a water supply system enabling the identification of critical trigger points at which the system would fail. The trigger points identified included maximum rainfall reduction percentage to maintain system functionality under increased demand and minimum initial storage beyond which the probability of failure increases rapidly. Additionally, a logistic regression model was developed for taking into consideration the cumulative effects of rainfall, demand and storage variations in order to predict the probability of failure of a water supply system. The study outcomes are expected to provide improved guidance to infrastructure system operators for enhancing the efficiency and reliability of water supply systems under threats posed by climate change and population growth impacts.

Water Loss Reduction as the Basis of Good Water Supply Companies’ Management

Companies using water distribution systems to reduce the operating costs and increase the reliability of water supply systems, as well as to protect disposable water resources, must search for ways to reduce water losses. The article points out the economic and environmental aspects of water losses. The possibilities of using international water loss assessment standards have been analysed. The reflections presented in the paper refer to the current trends and world standards in the field of water distribution systems management. The article presents the results and analysis of water losses for the water supply network operated by the Water Supply and Sewerage Company in Gliwice (Przedsiebiorstwo Wodociągow i Kanalizacji w Gliwicach, PWiK). The losses were determined on the basis of numerous indicators and compared with other distribution systems. At present, most indicators of water loss are at a very good or good level. The Infrastructure Leakage Index (ILI), as one of the most reliable loss indicators for the surveyed distribution system, assumed values from 3.33 in 2012 to 2.06 in 2015. The recent drop in ILI values indicates the effectiveness of the Company's strategy for water leakage reduction. The success comprises a number of undertakings, such as ongoing monitoring, pressure reduction and stabilisation, repairs and replacement of the most emergency wires.

Risk-Based Framework for Improving Customer Satisfaction through System Reliability in Small-Sized to Medium-Sized Water Utilities

AbstractSmall-sized to medium-sized water utilities (SMWU) face severe challenges to maximize the customer satisfaction (CS) because of operational failures, limited trained staff, and financial issues. Conventional methods are based on performance benchmarking and interviews, which might not be feasible at all times for SMWU. A novel risk-based framework is developed for improving CS by improving the reliability of water supply systems operating in a utility. The framework is primarily based on comprehensive analysis of customer complaints and staff’s observations on related complaints. Customer dissatisfaction is evaluated in terms of risk of not meeting CS, which starts when a customer reports a complaint; however, a complete evaluation of CS depends on the duration between the time of the report and the response until the complaints’ full resolution. Different categories of complaints are identified from an exhaustive record of a medium-sized utility in Okanagan Basin (British Columbia, Canada). For r...

The impact of the variability and periodicity of rainfall on surface water supply systems in Scotland

This paper analyses the impact of the variability and periodicity of rainfall on the reliability of water supply systems in Scotland. A conceptual rainfall-runoff model was used to simulate catchment runoff, and the reliability of 29 notional and six actual reservoirs was calculated using a simple storage model. The relationship between water supply reliability and the variability of rainfall was then investigated using different measures of variability. A strong correlation was found between reservoir reliability and measures representing the distribution of rainfall between the winter and summer seasons, as well as the cumulative sum (CUSUM) of annual precipitation, quantifying the variability of rainfall between years. In contrast, mainly the intra-annual CUSUM range and the variance of monthly precipitation influenced the reliability of river-intake schemes. The presence of periodic patterns in rainfall anomalies was found to be more prevalent in West Scotland, where reservoir reliability is on average lower than in the East. In addition, a sensitivity analysis revealed the small influence of evapotranspiration on reservoir reliability in comparison to rainfall variability. This study reveals the measures of variability most affecting the reliability of surface water supplies in Scotland, and could therefore help with their management in the context of future climate change.

Optimization of Electrical Energy Consumption and Level Reliability of Water Supply System

Generally, high operational cost is associated with all water supply system. This is as a result of the high amount of electric energy consumption ascribed to the system due to its components. The water supply system of the Mara-Japan Industrial Institute (MJII), Beranang, Selangor is one of such system that suffers this challenge of high operational cost. In this paper we have applied the use of an Adaptive Weighted Sum Genetic Algorithm to optimize the system operations such that it minimizes the high energy consumption as well as ensuring the overall reliability of the water level in the reservoir. The results obtained from the optimized model of the system show a promising and a significant reduction to the tune of 34.97% in the amount of energy consumed as compared with that of normal operations.

Нормирование требований надежности систем водоснабжения Вьетнама

Нормирование требований надежности систем водоснабжения Вьетнама

Анализ автоматизированных программ расчета водопроводных сетей в целях гидравлического моделирования при реновации трубопроводов

Operation of present-day water supply networks and management of hydraulic models of pipeline networks are labour intensive and ambiguous tasks requiring a sophisticated approach. Operation of water supply networks servicing major Russian cities is accompanied by processing of extensive amounts of information; moreover, some elements of the water supply infrastructure are hidden under the ground. Nowadays operators of water supply networks take advantage of the advanced software used to solve a wide range of tasks associated with data filing, overall evaluation, analysis and optimization of the most important parameters of urban water supply networks. The above software is an essential tool in the management of water networks in major cities. Their ability to collect and process all data on water supply networks and to conduct some research aimed at the improvement of various parameters of the system, including optimization of hydraulic characteristics of the pipeline is employed by researchers and water pipeline operators.The authors analyze and compare CAD software systems designated for water supply networks servicing big cities, capable of resolving multi-component problems and ensuring the reliability of water supply systems.

Integrated risk assessment of urban water supply systems from source to tap

Urban water supply systems (UWSS) are generally composed of water sources, transmission pipes, treatment plants, and distribution networks from source to tap and usually are exposed to variety of uncertain threatening hazards. These threats can be divided to three main groups of natural, human-made, and operational hazards which affect either water quantity or water quality. In order to evaluate the reliability of water supply systems, risk assessment tools must be used to identify threats, their probability, and consequences and vulnerabilities of each element of these systems against the hazards. Due to the complexity and uncertainties affecting water supply systems and threatening hazards, a comprehensive and effective risk assessment method is required. In this study, an integrated fuzzy hierarchical risk assessment model for water supply systems (IFHRA-WSS) is proposed to assess hazards in a complex UWSS using a systematic approach incorporating both water quantity and quality issues. This model uses a hierarchical framework for breaking down the UWSS infrastructures to their interrelated elements to reduce the overall complexity of the system. It also considers uncertainties using Fuzzy Logic approach. Effects of functional interdependencies between different components of the system have also been considered in the vulnerability analysis. IFHRA-WSS incorporates the contributions of urban water experts in a group risk assessment procedure in a way that they can be easily expressed in terms of the qualitative and quantitative risk measures. Efficiency of this model has been examined in a case study which includes a large part of a drinking water supply system in a major city in Iran. This system includes all the elements of the UWSS from the delivery point to the consumption point. In the case study, different components and subcomponents of this system have been ranked based on their estimated risk values. It is envisaged that the results of the proposed model can help the decision makers to plan for effective risk mitigation measures.