Water Use Efficiency Current Status Assessment in the Context of WATenERgy CYCLE Project

Water use efficiency is a crucial issue in drinking water utilities as it is connected to environmental and economic consequences. WATenERgy CYCLE project aims at developing a methodological approach towards efficient and effective transnational water and energy resources management in the Balkan–Mediterranean area. The paper presents the results of performance evaluation of the water supply systems of the water utilities involved in the project, both at local and national level. The methodology used in the water balance and performance indicators as well as data on the operational status of the water supply systems. The results showed that Non-Revenue Water is one of the major problems addressed

Total and Specific THMs’ Prediction Models in Drinking Water Pipe Networks

Although disinfection is a crucial process for the safety of drinking water, it is responsible for the formation of disinfection by-products (DBPs) being accused of severe health problems. The present study presents the development of models predicting trihalomethanes (THMs) in a drinking water supply system in Greece. Although some of the developed models can be used for the prediction of THMs, they are site-specific and cannot be used extensively

Identification of Suitable Locations in a Small Water Supply Network for the Placement of Water Quality Sensors Based on Different Criteria under Demand-Driven Conditions

Drinking water quality monitoring in real time is of utmost importance to ensure public health. Although water utilities, following the related legislative framework, monitor drinking water quality through samplings, the likelihood of detecting contaminants in consumers’ taps is low, depending on the scale of the monitoring programme. Additionally, even if the monitoring frequency is high, there is a time delay since sampling and analysis processes take some time. The selection of suitable locations for the installation of online water quality sensors is a hard task for a water utility due to the complexity of the water distribution system, the limitations of certain network junctions which are not easily accessible, and the computational burden involved. This topic has been extensively studied in recent years and sophisticated methods have been developed using optimization techniques. However, small water utilities do not have the means to implement such tools. This paper applies a methodology to identify the suitable junctions for the installation of online water quality sensors based on different objectives and under demand-driven conditions. This paper utilizes the hydraulic simulation model of a standard network to set up the water quality simulation model. A thorough analysis of various contamination scenarios takes place with different injection nodes and at different starting injection times for 24 h. The latter relates to the contaminant’s spread due to varying water demand. After a thorough analysis of 816 scenarios, a prioritized list of the most suitable nodes for the installation of the sensors is available for each optimization objective. Comparing the prioritized list of nodes achieved from each single or multi-objective function, the detection probability is almost the same. The analysis revealed that, due to varying water demand conditions, the ranking of the proposed nodes suitable for the installation of water quality monitoring sensors differs. Thus, varying hourly water demand should be part of analyses seeking to get reliable results. © 2022 by the authors

Disinfection Impacts to Drinking Water Safety—A Review

Drinking water supply safety is of paramount importance for human health. Disinfection is considered as one of the most significant water treatment processes as it inactivates pathogens from drinking water. However, disinfection might have adverse effects in human health, as disinfection by-products, blamed for cancer and reproductive/developmental effects, are formed. Many predictive models and optimization tools are developed in the research. However, an early warning system integrating monitoring, modelling and optimization tools is lacking. The paper reviews the disinfection methods and the models developed so far and presents the basic principles for the development of an early warning system

Water Networks Management: New Perspectives

Real water losses in water distribution systems may well be considered a potential water resource, as the significant water volumes being wasted through these physical losses should be replaced eventually. Advanced tools and strategies can be used for the efficient and sustainable management of water resources toward circular economy. The present Special Issue presents new perspectives for water networks management. The 10 peer-reviewed papers collected in this Special Issue have been grouped in two categories—drinking water supply systems and water resources and irrigation systems. These papers are being briefly presented in this Editorial

Optimizing Water Age and Pressure in Drinking Water Distribution Networks

Water distribution networks suffer from high levels of water losses due to leaks and breaks, mainly due to high operating pressure. One of the most well-known methods to reduce water losses is pressure management. However, when the operating pressure in a water distribution network reduces, the time the water stays within the network (called water age) increases. Increased water age means deteriorated water quality. In this paper, water pressure in relation to water age is addressed in a water distribution network in Greece. Using simulation and optimization tools, the optimum solution is found to reduce water age and operating pressure at the same time. In addition, District Metered Areas are formed and water age is optimized

Determining Hazards’ Prevention Critical Control Points in Water Supply Systems

A drinking water supply system is an extraordinarily complex system—consisting of kilometers of pipes and various tanks, valves, pumps, and other equipment. This complexity makes it extremely vulnerable to physical, chemical, and/or biological hazards. Therefore, the vulnerability assessment of a drinking water supply system to identify the critical control points is absolutely necessary. This paper assesses the vulnerability of the drinking water supply systems. The assessment is elaborated in systems using water from surface water bodies and groundwater bodies. The critical control points are identified using a risk assessment methodology (identifying the probability of the hazard occurrence and its effect or severity) where the monitoring parameters, and the corrective actions are determined

Predicting the behavior of a pipe network using the "critical Z-score" as its performance indicator

The paper deals with pipe reliability assessment in two networks using the Discriminant Analysis and classification (DAC) method. The pipes of each network are divided in two groups based on whether they failed at least once (failures group) or not (successes group). Several scenarios resulting from combining pipe characteristics (such as length, diameter, wall thickness, operating pressure, grade, and product (fluid in the pipe), lifetime) are being analyzed. A sensitivity analysis of the data available takes place to check the stability of the results. The criterion of the "critical Z-score" is finally used as an indicator predicting the pipe's future state (fail or not). The goals for each network are to develop a model that can correctly classify network pipes to successes or failures; define the pipe characteristics to be "blamed" for the pipes' behavior; and predict whether a pipe will fail or not. Studying the results of the DAC method application at the case study networks, a SWOT analysis is attempted in order to find out whether and under which presuppositions DAC can be successfully applied to water pipe networks. (C) 2009 Elsevier B.V. All rights reserved

Evaluating the performance level of a water distribution network under unbalanced operating conditions - The case of Kos Town (GR)

The need for a common international terminology is growing the last few years regarding the performance evaluation of urban water distribution systems, due to the wide diversity of definitions used across the word (even within the same country). Thus, the IWA Task Forces on Water Losses developed an international standard approach to calculate the water balance of an water distribution system utilizing best practices around the world. In Greece the need for a common approach is even more urgent as the country faces severe water shortage problems and there is no place for water losses due to ignorance. Greek Water Utilities are far behind in applying appropriate indicators to safely calculate the water losses level and therefore design effective strategies to reduce it. The paper presents the results of the Kos Town (Kos island) project regarding the performance evaluation of its water network. The project's goals were to develop the system's water balance (based on the IWA guidelines), calculate several performance indicators and compare them to national and international relative data available. The final outputs were to: a) estimate the apparent and real losses levels; b) calculate the non-revenue water level and its cost; and c) provide solid proposals targeted to an effective water losses reduction policy. The difficulties faced during the whole attempt are also presented. © 2010 Taylor & Francis Group, London