International Journal of Innovative Research in Engineering and Management (IJIREM) ISSN (Online): 2350-0557, Volume-11, Issue-4, August 2024 https://doi.org/10.55524/ijirem.2024.11.4.2 Article ID IJIR2560, Pages 13-18 www.ijirem.org Innovative Research Publication 13 Modeling of Water Age in Distribution Systems- Case Study Raber Hasan 1 , and Mehmet Ishak YUCE 2 1,2 Department of Civil Engineering, Gaziantep University, Gaziantep, Turkey Correspondence should be addressed to Raber Hasan; Received: 18 June 2024 Revised: 3 July 2024 Accepted: 17 July 2024 Copyright © 2024 made Raber Hasan et al. This is an open-access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ABSTRACT- Ensuring water quality in water distribution systems (WDS) is crucial for public health. Water authorities aim to provide consumers with an adequate supply of high- quality water at optimal pressure. This study focuses on a segment of Erbil City's WDS to analyze hydraulic parameters and water quality, particularly water age, using observed and documented data. The primary objective is to determine the age of water as it travels within the distribution system. The research utilizes EPANET 2.2 for a comprehensive case study, with digital loggers monitoring pressure and ultrasonic flow meters measuring discharges. The findings are expected to help develop new water projects and improve existing infrastructure, contributing to responsible water management and public well-being. Access to clean drinking water significantly impacts society, the economy, health, and the environment. KEYWORDS- Water Distribution System, Water Quality, Water Age, Erbil City, EPANET I. INTRODUCTION Water Distribution Systems (WDS) are crucial for delivering safe, high-quality drinking water in adequate quantities to various consumers. These systems vary in design and complexity depending on local factors, but their primary function remains the same: to ensure a reliable supply of potable water. In transmission systems, large mains or tunnels transport raw water to Water Treatment Plants (WTPs), which undergo treatment processes such as coagulation, sedimentation, filtration, and disinfection. Treated water is then conveyed to storage facilities before distribution mains deliver it locally. Distribution mains distribute water through a network that may be branched or looped, with individual buildings connected via service pipes. Local utilities typically manage the external distribution network, while in-house systems are the responsibility of property owners [12]. Pumping stations are often required to maintain adequate pressure, particularly in areas where gravity alone is insufficient. Conversely, Pressure Reducing Valves (PRVs) are used in regions with excessive pressure. The system includes numerous manholes and valves for access and control and storage basins to balance pressure, manage demand fluctuations, provide reserves for firefighting, and ensure emergency supplies [12]. The pipe materials selection depends on pressure conditions, diameter, and corrosion risk. Historically, cast iron (CI) and ductile iron (DI) pipes have been prevalent, but plastic pipes like polyvinyl chloride (PVC) and polyethylene (PE) are also common. However, plastic pipes can introduce chemicals and support microbial growth [5]. Looped networks offer advantages over branched ones by providing alternative supply routes and improving water quality through better circulation. However, they may risk water discoloration due to sediment resuspension and may not self-clean as effectively as branched systems [3]. Ensuring a continuous supply of high-quality drinking water requires the proper design, operation, and maintenance of WTPs and WDS. Effective management practices, regular monitoring, and adherence to regulatory standards are imperative to safeguard public health and meet consumer expectations [15]. Water age, defined as the time a parcel of water spends in the system from source to consumption, is a crucial parameter for assessing water quality in WDS [6]. Operators aim to minimize water age to comply with regulations, maintain system pressure, and ensure customer satisfaction. In the U.S., the average water age typically ranges from one to three days [10]. High water age can lead to Disinfection By-Products (DBPs) and microbial contamination, which increase as disinfectant levels decrease over time [9]. Factors affecting water age include pipe size, network configuration, demand fluctuations, and external water sources [6]. Extended water age can result in sediment formation, chlorine consumption, microbial growth, and DBP formation [16]. Hydraulic models analyze water age, assessing the cumulative time water spends in the system. These models help evaluate water quality impacts, such as storage tank turnover, disinfectant residual loss, and DBP formation[17]. Unlike constituent analysis, water age analysis does not require additional calibration, making it a straightforward method based on hydraulic data [17]. Digital modeling simplifies real-world systems into mathematical forms, facilitating their study [14][18]. Simulations predict system responses under various conditions, aiding in safe and cost-effective analysis and planning[18]. Calibration and validation ensure model accuracy and credibility [11].