Black-box modeling of water quality in WDS for real-time control: case studies

Water quality is one of the most important factors in the design of Water Distribution Systems (WDS) because, to maintain the conditions of water age, residual chlorine, and other quality characteristics, the ability to adjust hydraulic conditions using control elements is necessary. Although there are different methodologies for the analysis of water quality dynamics, the continued development and application of new modeling alternatives and methodologies are important to better understand water quality deterioration in WDS and provide efficient tools for assessing water quality in real-time, especially within the context of forecasting the spread of contaminants or substances in the network over time. The ability to provide water quality information in real time would provide benefits under normal operating conditions and increase capabilities for fast responses in an unexpected pollution event, whether intentional or unintentional. Therefore, being able to use these new methodologies will enhance the capacity to develop and use adequate models to analyze different alternatives to quickly solve and control problems like the spread of a contaminant in a network. This study presents a black-box model using EPANET-MSX software to assess water quality in two existing WDS networks, Hillsborough County in Florida, USA, and Bogotá, Colombia. The methodology is based on (i) analysis of model input and output variables (ii) numerical simulation of network water quality in the aforementioned software (iii) data analytics comparing historical vs. simulated conditions and some additional scenarios. The purpose of this methodology is to estimate the sensitivity of existing models compared with the proposed model when subjected to different initial conditions.