Development and Validation of a GIS-Based Tool for Disinfection Byproduct Formation Prediction in Water Distribution Systems

Disinfection of water in distribution systems is essential for ensuring the microbiological safety of drinking water. However, disinfection byproducts (DBPs) are chemical compounds formed when disinfectants, such as chlorine, react with natural organic matter (NOM) and other constituents in water. The formation of DBPs in drinking water distribution systems can pose health risks, including cancer and reproductive issues, necessitating robust strategies to predict and mitigate their presence.

As part of the EU-funded IntoDBP project, a comprehensive real-world case study was conducted in Limassol, Cyprus, to investigate DBP formation within a water distribution system. The study included monitoring the hydraulic and water quality states of the system, from the Drinking Water Treatment Plant (DWTP) to end-users. This complete system perspective allowed for the evaluation of key factors affecting DBP formation, such as water source characteristics, residence time, and chlorination practices.

This work presents the process of creating a DBP modeling tool, detailing the methods used to address challenges related to the integration of heterogeneous data sources. Data from the DWTP, re-chlorination points, and distribution nodes were harmonized to ensure accurate representation of both hydraulic conditions and chemical reactions. Models capable of predicting DBP formation were developed as part of the study, with a specific focus on trihalomethanes (THMs) and haloacetic acids (HAAs). These models were validated using real-time data from sensors and manual sampling.

Alongside these models, a GIS-based software tool was developed to explore strategies for minimizing DBP levels within distribution networks. This tool visualizes data from multiple sources, including SCADA systems, water quality sensors, and GIS data, enabling dynamic simulations and scenario testing. Advanced simulation techniques using EPANET-MSX facilitated the simulation of multi-species reactions and the incorporation of uncertainties, such as variations in source water composition and operational conditions. The tool provides researchers and practitioners with the capability to evaluate and optimize chlorination practices, water mixing strategies, and operational configurations to mitigate DBP risks effectively.

Results from the case study highlighted the critical role of water residence time and source water composition in DBP formation. Nodes farther from chlorination points and those receiving water with higher NOM levels exhibited elevated DBP concentrations, emphasizing the importance of optimizing hydraulic and chemical parameters throughout the distribution system. The developed software tool demonstrated the potential of integrating GIS and hydraulic data with chemical analyses. It also showed promise in evaluating various mitigation strategies, including dynamic chlorination schedules and adjustments in flow management, within a realistic setup. This tool offers a valuable resource for researchers and water utility operators, providing a benchmark platform for developing and validating innovative DBP management strategies.