Changes simulation in a conventional ETA midsize to safe water production

ABSTRACT

This work involving the analysis of scenarios based on the proposition of operational and structural changes in water supply systems and their impacts on the quality of water supplied to the population. The aim of this study is to evaluate the impacts of structural and management alterations proposed for the water treatment plant on water quality in the network, based on the simulation of the behavior of free residual chlorine (FRC), as well as to evaluate the reduction the risks to the health of consumers, through the application of risk analysis method Failure Mode and Effect Analysis (FMEA), aiming a safe supply for the population of a medium-sized city. The simulation of water quality behavior was developed in the software EPANET 2.0, being the network map constructed from the network tracing of water supply network of two places of Campina Grande City, Paraíba state, Brazil. In the current scenario (C1) one of the places presented, on all nodes, FRC below the minimum recommended by the Ordinance of Brazilian Health Ministry; after the changes, simulated in scenario 2 (C2) an improvement of 60% was observed in the disinfectant concentration compliance with the minimumrecommended value. The risk assessment for C2 showed that the changes provided a reduction of about 66% of the risks in relation to C1. The simulation indicated that there is an improvement in the quality of water but it was concluded, however, that only promoting changes in the water treatment plant is not sufficient to ensure the same or higher concentrations of FRC equal or superior to 0.2mgCl₂ /L, throughout the network.

Keywords:  Water supply system; Water quality; free residual chlorine; Risk assessment; EPANET