Evaluation of the groundwater quality and hydrogeochemistry characterization using multivariate statistics methods: case study of a hydrographic basin in Brazil

Brazil is a country with different physical and climatic conditions, located in a diverse range of geological structures and abundant in water resources. Among the aquifers present in southern America, the Guarani and Serra Geral aquifer are two of great importance to the population. With the need to improve the quality of groundwater and to present more scientific studies on these groundwater sources, the objective of this study was to use cluster analysis and principal component analysis/factor for hydrogeochemical characterization and groundwater quality and correlate these findings with contaminants from human activities. This study was divided into two steps, hydrogeological characterization, and analysis of some contaminants that cause negative impacts on human health. The study area was a hydrographic basin located within Maringá, Paraná, Brazil. The results demonstrate that the groundwater of this basin has the dominant hydrogeochemical characteristic of calcium bicarbonate type and sodium carbonate type. The hierarchical cluster analysis was effective to the hydrogeological characterization and classified 18 sources in three distinct clusters. It was possible to correlate pollution sources that were contributing to the decline of the quality of this basin. Nitrate and benzene were related to the main pollution originating from the urban area; manganese, chromium, and lead from the old landfill; nickel and copper from electroplating industries; and pesticides atrazine and diuron, were related to the agricultural activities. The present study is of great relevance, because, in addition, to characterize the type of water (hydrogeochemical), it allowed to identifying harmful contaminants to human health in the region by correlating them with their origin.