Drinking Water Distribution Networks Research Articles

Automated GIS-based decision tool for rehabilitation of a drinking water infrastructure in Tlemcen, Algeria

Water resource management relies heavily on the utilization of decision-making systems to guide the strategic rehabilitation and renovation of infrastructure within water distribution networks (WDNs). This study aims to develop and apply a scripting tool in ArcGIS for decision-making in WDN. It combines a collection of decision support systems, including Geographic Information Systems (GIS) and multi-criteria analysis, for infrastructure renovation and rehabilitation. The research is divided into two main sections. The first focuses on creating and implementing the analytic hierarchy process tool in ArcGIS, while the second discusses its application in the study area, which is the drinking water distribution network of an urban area in Tlemcen, located in the Northwest of Algeria. The study’s results reveal that 25% of the network is in critical condition and require immediate rehabilitation. Sixty-two percentage of the network is classified as moderately urgent, indicating a pressing but less immediate need for intervention. Finally, the remaining 13% of the network requires attention over a longer timeframe for rehabilitation. The main criteria influencing pipe prioritization are material (26% of total weight), laying date (26% of total weight), and pressure (20% of total weight). This developed tool can be easily adapted and applied by engineers and water management officers. It serves as a guide for decision-makers and planners in urban water management in Tlemcen and can be replicated and applied to other areas worldwide.

Detection of Pharmaceutically Active Compounds in Tap Water Samples by Direct Injection HPLC/MS-MS: A Danger Signal in Deficiency in Residue Management.

To date, there is an increased risk to public health and the environment due to the presence of pharmaceutically active compounds within drinking water supply and distribution networks. Owing to this, a direct injection-HPLC/MS-MS method was developed for the simultaneous determination of 16 active pharmaceutical compounds in tap water samples: amoxicillin, ampicillin, cephalexin, cefotaxime, cefuroxime, ciprofloxacin, clarithromycin, clindamycin, chloramphenicol, cyproterone, erythromycin, flutamide, spironolactone, sulfamethoxazole, tamoxifen, and trimethoprim. Limits of detection (LOD) ranged from 0.2 to 6.0µg/L while quantification limits (LOQ) from 0.3 to 20µg/L. Recovery percentages were between 70 and 125%. Total analysis time was short, with all compounds being resolved in less than 2.1min. Of the 22 tap water samples collected and analyzed, the highest concentrations corresponded to amoxicillin (147µg/L) and ciprofloxacin (44µg/L). The findings could set a precedent for establishing safe levels of these compounds and increasing standards for tap water quality in this region.

Development of a user-friendly hydraulic model for simulating hybrid water distribution networks: a transition toward sector sustainability

ABSTRACT The conventional computational approach for modeling and simulating drinking water distribution networks (WDNs) is time-consuming and prone to human errors. Therefore, this study developed and implemented a hydraulic modeling tool, the ‘Kyema-Net model’, based on the modified Hardy Cross algorithm in Visual Basic, to simulate a hybrid WDN with the inclusion of pipe cost assessment. The model's accuracy was validated by comparing its outputs with those of EPANET 2.2 software. The Kyema-Net model and EPANET 2.2 simulation results were comparable. Considering the WDN case study, the proposed model initialized nodal inflows in proportions of 60 and 40% for any two pipes exiting the node, reducing the computational steps. The model executed three trials to achieve the final solution against four trials for EPANET 2.2. The mean absolute percentage error, coefficient of determination (R2), and root mean square error metrics for flow velocity were ∼0.00%, 1.00, and ∼0.00 m, respectively. The modified resilience index values ranged between 0.30 and 1.09. Implementing the proposed hydraulic modeling tool in designing and/or rehabilitating WDNs demonstrated compliance with numerous social-, economic-, and technological-related Sustainable Development Goals. This would assist various water sector stakeholders in the sustainable planning, operation, and management of WDNS globally.

Advantages of the Event Method for the Simulation of Water Quality in Pressurised Water Systems

In this paper, several methods for the calculation of water quality evolution in drinking water distribution networks are analysed. The Lagrangian Time-Driven method has been implemented in the Epanet simulation software since version 2.0. In version 2.2, some improvements were implemented to deal with mass imbalances (Lagrangian Time-Driven improved method). However, it sometimes presents inaccuracies in calculations, especially when there are short-length pipes. To solve this problem, the implementation of the Lagrangian Event-Driven method is proposed, which provides more accurate quality results. In order to detail the differences and similarities of the results of the different methods and to determine under what conditions the results provided by Epanet are sufficiently adjusted, two practical examples have been carried out, one of them on a hydraulic model of a real network.

Study on Drinking Water Distribution System at Sekaran District Service Area in Lamongan Regency

Drinking Water Supply System (SPAM) organizers needs to carry out its duties and functions to fulfil the quality, quantity, and continuity for the community. From all SPAM service areas in Sekaran District, there are three villages, namely Manyar, Jugo, and Trosono Village which lack access to water. The three villages water pressure falls below the minimum pressure requirements of Minister of Public Works and Housing Regulation Number 27/RT/M/2016. Seeing that the continuity is not optimal, it is important to study the drinking water distribution network of one of the SPAM in District Sekaran service areas. Recommendations for pipeline network restoration involves conducting hydraulic simulation using EPANET 2.2 which identified the need to parallelize existing pipes and establish a new pipe with a diameter of 200 mm and a length of 1960 m that connects Ngarum Village and Jugo Village. In addition, expanded reservoir capacity is required to meet water demand because it will increase during the development year. Furthermore, based on the results of the demand pattern measurement, the pump schedule must be modified, as well as the quantity of functioning pumps to be able to meet the water supply demand when the development occurs.

Introducing bacterial community turnover times to elucidate temporal and spatial hotspots of biological instability in a large Austrian drinking water distribution network

Ensuring biological stability in drinking water distribution systems (DWDSs) is important to reduce the risk of aesthetic, operational and hygienic impairments of the distributed water. Drinking water after treatment often changes in quality during transport due to interactions with pipe-associated biofilms, temperature increases and disinfectant residual decay leading to potential biological instability. To comprehensively assess the potential for biological instability in a large chlorinated DWDS, a tool-box of bacterial biomass and activity parameters was applied, introducing bacterial community turnover times (BaCTT) as a direct, sensitive and easy-to-interpret quantitative parameter based on the combination of 3H-leucine incorporation with bacterial biomass. Using BaCTT, hotspots and periods of bacterial growth and potential biological instability could be identified in the DWDS that is fed by water with high bacterial growth potential. A de-coupling of biomass from activity parameters was observed, suggesting that bacterial biomass parameters depict seasonally fluctuating raw water quality rather than processes related to biological stability of the finished water in the DWDS. BaCTT, on the other hand, were significantly correlated to water age, disinfectant residual, temperature and a seasonal factor, indicating a higher potential of biological instability at more distant sampling sites and later in the year. As demonstrated, BaCTT is suggested as a novel, sensitive and very useful parameter for assessing the biological instability potential. However, additional studies in other DWDSs are needed to investigate the general applicability of BaCTT depending on water source, applied treatment processes, biofilm growth potential on different pipe materials, or size, age and complexity of the DWDS.

Optimization model the pipe diameter in the drinking water distribution network using multi-objective genetic algorithm

Optimization model the pipe diameter in the drinking water distribution network using multi-objective genetic algorithm

MUNICIPAL INFRASTRUCTURE AT THE LEVEL OF PROTECTED NATURAL AREAS ROSCI0045 JIU CORRIDOR, BISTREȚ ROSPA0010 AND NATURAL RESERVES DRĂNC FOSSIL PLACE-2391 AND ZAVAL FOREST - IV.33 + A6

The paper aims to highlight the aspects related to the urban infrastructure for the protected areas ROSCI0045 Jiu Corridor, Bistreț ROSPA0010 and the Drănic Fossil Place-2391 and Zaval Forest Nature Reserves – IV.33+A6, given that they group a significant number of species of plant and animal origin. These protected areas play an essential role in biodiversity conservation at the level of the 56 ATUs (37 in Dolj County, 17 in Gorj County, one in Mehedinţi County, one in Olt County), on whose territory they are located. The paper refers to the drinking water distribution network, the sewerage network and the natural gas distribution network (including adjacent aspects related to them).The area has 740 km of city streets, of which 578 km modernized, 1971.2 km drinking water network, 936.0 km sewerage network, produces about 342 thousand cubic meters of water per day, achieving a daily consumption of 19,956 cubic meters. Within the area, there are 940.2 km of pipelines for natural gas distribution (two thirds located in the urban area), which facilitated a consumption of 133,040 thousand cubic meters of gas annually. The urban infrastructure improved during 2017-2021, but certain aspects related to it need to be properly analyzed in order not to have a high negative impact on the state of the environment.

Investigating the Residue of Diazinon, Chlorpyrifos, and Dichlorvos in Urban Drinking Water Supply Sources and Determining the Water Quality Index in Tirano-Korun in 2020

Introduction: Contamination of water sources with toxins is an environmental problem and a serious threat to the health of societies. This study aimed to ascertain the remaining levels of toxins in urban drinking water networks and compute the water quality index.
 Materials and Methods: To examine the residual concentration of diazinon, chlorpyrifos, and dichlorvos in urban drinking water distribution networks, 35 underground and surface water sources were sampled in Tiran-o-Korun in Isfahan province, Iran. GC-ECD device was used to analyze the samples.
 Results: Diazinon was not observed in any of the sampling seasons. The maximum concentration of chlorpyrifos and dichlorvos was 61 and 100 ppb, respectively. Although chlorpyrifos was seen more in the hot season and dichlorvos in the cold season, the mean concentration of these toxins in different seasons was lower than the guidelines of Iran and the World Health Organization (WHO). The mean concentration of nitrate, and hardness, in wet and dry seasons was 46.23 and 46.42, and 343.7 and 338.8 mg/l, respectively.
 Conclusion: The mean and standard deviation of quality index of Iran's water resources (IRWQI) in wet and dry seasons were 52.16 ± 45.3 and 50.69 ± 15.8, respectively. The residual concentration of toxins in some water sources of this city exceeded the guidelines of Iran and the WHO in summer and spring.

Application of the NSGA-II multi-objective algorithm in the optimal design of drinking water distribution networks. Case: Huancavelica City, Peru

En los últimos tiempos, se han desarrollado diversos algoritmos genéticos multiobjetivo y su aplicación en optimización de redes de distribución de agua potable, de los cuales NSGA-II ha mostrado un desempeño más sólido. Esta investigación muestra la aplicación de NSGA-II en el diseño óptimo de redes de distribución de agua potable considerando costo (IC) y confiabilidad hidráulica (IR) como funciones objetivo. La investigación se realizó en respuesta a un problema real relacionado con el suministro de agua en la ciudad de Huancavelica. Mediante la información obtenida a través de la EPS EMAPA Huancavelica S.A., y el lenguaje de programación Python con el Toolkit de Epanet se valida NSGA-II aplicándolo al diseño de la red de Hanoi. Una vez validado, se analiza la red de Huancavelica que cuenta con un IC de 0.31 equivalente a USD 140 099.89 y un IR de 0.25 y se obtiene un diseño óptimo de red que precisa un IC de 0.24 con un valor de USD 117 590.12 y un IR de 0.23; lo cual permite apreciar una diferencia en el IC de USD 22 509.77 y una reducción del IR, que la hace una red mucho más confiable que satisface simultáneamente las restricciones de presión mínima en todos los nudos, además de garantizar condiciones de falla durante su operación. Se determinó que NSGA-II es favorable para el diseño óptimo de redes de agua potable considerando dos funciones objetivo de costo y confiabilidad hidráulica.

Formation of disinfection by-products within the drinking water production system and distribution network of a real case study

This work presents a collaboration between the so-called Gasset Service Association (responsible for providing drinking water to 100,000 inhabitants from a surface water reservoir) and researchers from the University of Castilla-La Mancha (Spain). The main aim of this work was providing a comprehensive characterization of the formation and removal of disinfection by-products in a real drinking water treatment plant (DWTP) and water distribution network. According to the results obtained, it can be stated that bromate is formed on the pre-oxidation stage and it is not eliminated throughout the DWTP; meanwhile, total organic carbon is partially removed on the clarification process. Moreover, it demonstrates the key role of the residence time and the type of water storage throughout the distribution network (either in pipes or in tanks) due to the combined effect of, at least, four overlapped mechanisms: THMs chemical generation, air stripping, hydrolysis and biological removal. This comprehensive view of the drinking water production and distribution network represents an excellent framework for allowing the improvement in the drinking water quality for a very common water production case study: a medium-size city fed by a surface water source.

Using water quality parameters to prediction of the ion-based trihalomethane by an artificial neural network model.

Trihalomethanes (THMs) are the first disinfectant by-products in the drinking water distribution network and are classified as potential carcinogens. The presence of THMs in chlorinated water depends on the pH, water temperature, contact time between water and chlorine, type and dose of disinfection, bromide ion concentration, and type and concentration of natural organic materials (NOMs). In the present study, the formation of THMs was evaluated by six simple and easy water quality parameters and modeled by an artificial neural network (ANN) approach through five water distribution networks (WDNs) and the Karoun River in Khuzestan province. The results of this study that was conducted from October 2014 to September 2015 showed that THM concentration ranged in five WDNs, including Shoushtar, Ahvaz (2), Ahvaz (3), Mahshahr, Khorramshahr, and total WDNs through N.D.-9.39µg/L, 7.12-28.60, 38.16-67.00, 17.15-90.46, 15.14-29.99, and N.D.-156, respectively. The concentration of THMs exceeded Iran and EPA standards in many cases in Mahshahr and Khorramshahr WDNs. Evaluation of R2, MSE, and RMSE showed the appropriate correlation between measured and modeled THMs, indicating a reasonable ANN potential for estimating THM formation in water sources.

Data-Driven Identification of Dynamic Quality Models in Drinking Water Networks

Traditional control and monitoring of water quality in drinking water distribution networks (WDNs) rely on mostly model- or toolbox-driven approaches, where the network topology and parameters are assumed to be known. In contrast, system identification (SysID) algorithms for generic dynamic system models seek to approximate such models using only input-output data without relying on network parameters. The objective of this paper is to investigate SysID algorithms for water quality model approximation. This research problem is challenging due to (1) complex water quality and reaction dynamics; and (2) the mismatch between the requirements of SysID algorithms and the properties of water quality dynamics. In this paper, we present the first attempt to identify water quality models in WDNs using only input-output experimental data and classical SysID methods without knowing any WDN parameters. Properties of water quality models are introduced, the ensuing challenges caused by these properties when identifying water quality models are discussed, and remedial solutions are given. Through case studies, we demonstrate the applicability of SysID algorithms, show the corresponding performance in terms of accuracy and computational time, and explore the possible factors impacting water quality model identification.

Twitter Data Mining for the Diagnosis of Leaks in Drinking Water Distribution Networks

This article presents a methodology for using data from social networks, specifically from Twitter, to diagnose leaks in drinking water distribution networks. The methodology involves the collection of tweets from citizens reporting leaks, the extraction of information from the tweets, and the processing of such information to run the diagnosis. To demonstrate the viability of this methodology, 358 Twitter leak reports were collected and analyzed in Mexico City from 1 May to 31 December 2022. From these reports, leak density and probability were calculated, which are metrics that can be used to develop forecasting algorithms, identify root causes, and program repairs. The calculated metrics were compared with those calculated through telephone reports provided by SACMEX, the entity that manages water in Mexico City. Results show that metrics obtained from Twitter and phone reports were highly comparable, indicating the usefulness and reliability of social media data for diagnosing leaks.

Modelling of corrosion rate in the drinking water distribution network using Design Expert 13 software.

This study is focused on the modelling of the composite effect of corrosion factors using Design Expert 13 software on the corrosion rate in the water distribution network of Patna (Bihar), India. A total of nine variables, including pH, temperature, total dissolved solid (TDS), alkalinity, calcium hardness, chloride, sulphate, dissolved oxygen (DO) and time, were considered for modelling. The physicochemical parameters were determined through regular monitoring of water samples. The corrosion rate was determined by the direct monitoring of water distribution pipes using adjustments of seven GI coupons for 45, 90, 135, 180, 225, 270 and 315days. Modelling was performed for various corrosion factors using the low-level and high-level experimental ranges. Nine of the corrosion factors, i.e. pH, temperature, TDS, alkalinity, calcium hardness, chloride, sulphate, DO and time, were considered in this study. The data used for low-level and high-level range were 7.28, 23, 430, 115, 24, 18, 10.94, 3.5 and 0 and 7.86, 28, 704, 284, 180, 98, 38.7, 6.8 and 315, respectively. Using the Box-Behnken design (BBD), 160 runs were conducted, including ten replicates at the central point of each block. The results of ANOVA indicate that the values of R2, adjusted R2 and predicted R2 are 0.9714, 0.9507 and 0.8941, respectively. The value of R2 (0.9714) was close to 1, which indicates a good fit. The adequate precision was found to be 30.8442, indicating a good signal. The coefficient of variance discusses reproducibility, and in this case, it was 9.90%. On the basis of the ANOVA result, the quadratic model is well-fitted and can be accepted as a suitable model. A total of seven parameters, such as chloride, sulphate, hardness, alkalinity, pH, calcium and hardness, were used for the design of the experimental corrosion rate (CR). Corrosion rate as observed by direct monitoring of the water distribution system was 1.37, 3.08, 1.90, 1.38, 1.09, 2.05 and 1.45 MPY for 45, 90, 135, 180, 225, 270 and 315days, respectively. These individual CR versus synthetic aqueous solutions were used to validate the interaction of the response surface. It was observed that the trend of individual corrosion rates in synthetic aqueous solutions and the interaction of composite variables with corrosion rates in a quadratic model of response surfaces were clearly correlated.

Theoretical Estimation of Disinfectant Mass Balance Components in Drinking Water Distribution Systems

The water quality audit concept is an important feature in assessing the loss of disinfectant mass in drinking water distribution systems. Based on this concept, the loss can be divided into the loss of disinfectant mass through water losses (Ml) and the decay of disinfectant mass due to chemical reactions (Mr). When an audit focuses on the effect of water losses on the loss of disinfectant mass, the decay of disinfectant mass by chemical reactions with the ideal condition of no water losses (Mro) has to be estimated; thus, the disinfectant mass associated with water losses (MWL=Ml+Mr−Mro) can be assessed. Generally, the computation of these components (Ml, Mr, and MWL) needs hydraulic and water quality modeling. In this study, we propose a novel method based on a simple theoretical analysis to evaluate these components using only two parameters: the ratio of water losses (p) and the ratio of disinfectant concentrations at the critical pressure point and the network inlet (Cp*). The coefficients of our theoretical Ml, Mr, and MWL were estimated using 20 real network models, with p between 2.8% and 54.9% and Cp* between 18.4% and 91.9%. The results showed that our equations were effective at assessing the loss of disinfectant mass in drinking water distribution networks for the top-down auditing approach.

Assessment of the Performance of a Water Treatment Plant in Ecuador: Hydraulic Resizing of the Treatment Units

Granting access to drinking water has been a challenge because 47% of the worldwide population is not connected to a drinking water distribution network in rural settlements. This study aimed to evaluate the contaminant removal efficiency in a conventional water treatment facility in the Austro region of Ecuador, Paute, to identify the treatment units requiring hydraulic resizing. Water samples were collected from each treatment unit to characterize the physical-chemical and microbiological parameters, and the dimensions of the treatment ponds for hydraulic evaluation purposes. Water hardness, electrical conductivity, SO42−, and Fe2+ were the main issues found in the water, which failed to comply with Ecuadorian technical guidelines. The treatment units, such as the flocculator, rapid sand filter, and storage tank, were resized to meet the demand of the future population. In addition, the residual free chlorine was measured as insufficient in the community’s tap water, showing an unprotected water distribution system to microbiological contamination. No disinfection by-products were found despite the existence of biodegradable organic matter. The findings of this research propose improvements in the deployed treatment practices to provide the community with drinking water in accordance with the Sustainable Development Objectives (SDG 3 and SDG 6).

Health risks due to intrusion into the drinking water distribution network: hydraulic modelling and quantitative microbial risk assessment

This work provides a valuable application of the QMRA framework in a real distribution network, using available data from the water supplier and validated with other readily available sources.

Predicting iron exceedance risk in drinking water distribution systems using machine learning

A Machine Learning approach has been developed to predict iron threshold exceedances in sub-regions of a drinking water distribution network from data collected the previous year. Models were trained using parameters informed by Self-Organising Map analysis based on ten years of water quality sampling data, pipe data and discolouration customer contacts from a UK network supplying over 2.3 million households. Twenty combinations of input parameters (network conditions) and three learning algorithms (Random Forests, Support Vector Machines and RUSBoost Trees) were tested. The best performing model was found to be Random Forests with input parameters of iron, turbidity, 3-day Heterotrophic Plate Counts, and high priority dead ends per District Metered Area. Different exceedance levels were tested and prediction accuracies of above 70% were achieved for UK regulatory concentration of 200 µg/L. Predicted probabilities per network sub-region were used to provide relative risk ranking to inform proactive management and investment decisions.

Geolocalization of water-waves origin within water distribution networks using time reversal of first event detection

Drinking water distribution networks in urban areas are daily subject to fast propagating pressure waves resulting from routine operations. These water-hammer waves lead to structural aging and facility damages, the origin of which is not easy to find but are sometimes of high managerial interest. In this contribution, we demonstrate that using a reasonable number of high-frequency pressure detectors distributed within the network combined with a proper post-processing method permits a close geolocalization of the damaging wave origin. The method is first tested and validated on a real water distribution network having approximately 26000 pipes, whereas considering a known, prescribed waveorigin, so that the sensitivity to sensor number (sensor spatial density), sensor location and signal-to-noise ratio on the geolocalization robustness are analyzed in detail. It is then applied and illustrated over real sensor recordings the result of which are validated on the field from history matching. This paper thus presents the first field-scale geolocalization of water-hammer events origin test as well conditions for which, given sensor density and signal-to-noise ratio, the geolocalization success is to be expected.