Avaliação espaço-temporal de parâmetros da qualidade da água bruta de poços urbanos utilizados para consumo humano

Abstract

The water quality for human consumption must meet potability standards established in the Brazilian legislation, Ordinance GM/MS 888/2021, as water can carry a large amount of microbiological and/or physicalchemical contaminants that cause diseases. The present study used open data on the results of the microbiological and physicochemical characteristics of raw water from nine artesian wells from 2016 to 2021 registered in the VIGIAGUA Program in the city of Ponta Grossa - Paraná. A total of 296 samples were analyzed, verifying compliance with the potability standards for human consumption, according to basic parameters of total coliforms (TC), E. coli, turbidity and fluorides stipulated by the National Guideline of the Water Sampling Plan. For the statistical analyses the Kruskal-Wallis test was used, followed by the post-hoc Dwass-Steel-Critchlow-Fligner (DSCF), and Spearman correlation test was used to assess the association between variables. In addition, a qualitative spatial analysis of the possible risks of microbiological contamination and vulnerability maps of the wells were carried out using sanitary inspection form, defined by the World Health Organization. The results indicated raw water contamination by TC and E. coli in 34% and 7% of the samples evaluated, respectively. Results of turbidity and fluoride met the recommendations of the Brazilian legislation in 99% of the samples, with averages of 0.46 uT and 0.19 mg.L-1 and medians of 0.22 uT and 0.15 mg.L-1

, respectively. The results showed that rainfall 48 hours before the collection of the water samples influenced the increase of the water contamination for both microbiological parameters (p < 0.05). From the vulnerability maps and field visits, the precariousness of some artesian wells installed in the city of Ponta Grossa was observed, with consequences for the groundwater quality. The spatio-temporal mapping and the risk matrix for ingestion of the contaminated water by E. coli, developed to present the results of this research, can help public managers in public health and sanitation actions in the city of Ponta Grossa.