Author(s): Stefania Piazza; Gabriele Freni
Linked Author(s): Gabriele Freni
Keywords: Contaminant intrusion; Numerical modelling; Water distribution networks
Abstract: This work develops a numerical model based on the EPANET-DD (dynamic dispersion) model to simulate sodium chloride (NaCl) intrusion through a leak under negative pressure and the subsequent advective–diffusive–dispersive transport of the contaminant in the water network. The model solves the solute transport equation under variable flow conditions using the random walk method, including axial and transverse dispersion processes in the pipelines and coupling the quasi-steady hydraulic simulation with the calculation of mass transport. Based on the study by Fontanazza et al. (2015), contaminant intrusion was simulated by imposing a transient subatmospheric pressure event (e.g., a water hammer) at a leak, causing the impulsive influx of NaCl into the pipeline. The model was calibrated and validated by comparing the simulations with experimental data obtained in the study by Fontanazza et al. (2015), showing an excellent ability to reproduce both the peak concentration and the propagation of the contaminant along the network.
Year: 2026