Water quality parameters in source water: multivariate analysis of surface water and groundwater supply on data from 4 supply systems in Brazil

Abstract

In this research, multivariate statistical analysis was performed to assess the water quality of 4 important drinking water sources in the state of Rio Grande do Sul (RS), Brazil. For this, nineteen water quality parameters (WQP) were applied twice a year, for the period 2013-2018, to assess water quality from different sources. The evaluation was conducted on tree water surface (SWS) and one groundwater source (GWS), separately. Analysis of outliers, Shapiro-Wilk normality test, non-parametric Kruskal-Wallis test, Spearman correlation analysis, hierarchical cluster analysis and the Ward method were carried out to identify the quality of water from different sources. There were higher coefficients of variation for metals, color, turbidity, and total phosphorus. The multivariate analysis pointed out that variables with the highest correlation and grouping in the springs indicate the movement of soil particles into water bodies and their degradation, due to the lack of protection in the areas of these relevant sources of supply.