WATER QUALITY DISTRIBUTED BY TREATMENT PLANTS IN SERGIPE BETWEEN 2014 AND 2021: SYNTHESIS OF INDICATORS AND MULTIVARIATE ANALYSIS

Abstract

This study evaluated the quality of treated water supplied by six Water Treatment Plants (WTPs) in the state of Sergipe, Brazil, from 2014 to 2021, using previously systematized secondary data from the Drinking Water Quality Surveillance Information System (SISAGUA) and the Sergipe Sanitation Company (DESO). Residual chlorine, turbidity, and total coliforms were analyzed through compliance assessment with drinking-water standards, synthesis by a relative quality indicator, and multivariate interpretation using GT Biplot. The indicator was used as a comparative and non-normative measure, with interpretation based on consolidated results and without numerical extrapolations not supported by the available raw data matrix. The results indicated spatial and temporal variations among WTPs, supplied municipalities, and evaluated years, with relatively better performance in 2016 for most locations. Recurring non-compliant samples for total coliforms, fluctuations in residual chlorine levels, and episodes of increased turbidity were also observed, suggesting weaknesses related to disinfection, operational stability, and/or recontamination along the distribution network. The integrated use of indicators, compliance assessment, and multivariate analysis helped identify critical parameters and support decisions aimed at operational control and sanitary surveillance of the water supplied to the population.