Hydrochemical characterization of groundwater in the Municipality of Itu (SP)

Abstract

Hydrochemical study in Itu city (São Paulo State) was performed in the 1990s as part of a hydrogeological characterization related to the planning of groundwater use in the Sorocaba-Campinas region, an area of increasing urbanization and industrialization. Analytical results of 50 well samples indicated the predominance of calcium bicarbonate water in the Crystalline Aquifer, and of sodium to calcium bicarbonate water in the Tubarão Aquifer. The waters are considered to be appropriate for agricultural use and livestock. However, for human consumption, the water of some wells is not potable and does not meet the bacteriological standards of the Health Ministry (Ordinance 2914, of 12/12/2011), which is probably associated with problems of sanitary protection (presence of fecal coliforms in 5 wells and total coliforus in 13 wells). High concentrations of iron and/or manganese have also been observed in 16 wells and may be associated with geological features or construction problems. There is an anomalous concentration of fluoride probably related to mineral alteration of granitoid rocks.