Mapeamento hidrogeoquímico do município de Caçapava do Sul, RS

Abstract

The objective of this work was the hydrogeochemical mapping of the municipality of Caçapava do Sul by means of the geochemical characterization and potability of the waters. The methodology used consisted in the realization of campaigns of sampling and execution of analyzes and physical-chemical measurements of groundwater. Almost all households in the rural area of the municipality use groundwater as a supply, however there is no control as to the quality and potability of these waters. Hydrogeochemistry is the science that studies the chemical properties of groundwater and its relation to local geology. The following physicochemical analyzes of the water from the tubular wells were performed: color, turbidity, electrical conductivity, total alkalinity, pH, total dissolved solids, total hardness, calcium, magnesium, iron, sulfate, chloride and X-ray fluorescence. Caçapava do Sul includes the river basins of the Camaquã, Baixo Jacuí and Vacacaí-Vacacaí Mirim rivers with their respective hydrogeological domains and aquifer systems. The rocks of the Basement are metavulcanic, metassedimentary and crystalline, belonging to the Mantiqueira Province. In the Camaquã Basin volcanic rocks, volcano-sedimentary rocks and sedimentary sequences of Ediacaran, Cambrian and lower Ordovician ages are found. Finally, in the Paraná Basin there are sandstones, siltstones, conglomerates and carbonaceous shales. The results present the potability problems of the groundwater of the municipality of Caçapava do Sul. The analyzed parameters presented a significant variation in the composition of the groundwater of Caçapava do Sul. Escherichia coli, Staphylococcus aureus, and some trace constituents identified qualitatively through X-ray fluorescence.