Cláudia A. Ferreira^1,, Helena E. L. Palmieri², Maria Ângela de B. C. Menezes², Lúcia M. L. A. Auler²

This study deals with the hydrochemical characterization and water quality assessment of springs spread throughout the Iron Quadrangle (IQ) in the state of Minas Gerais, Brazil. In the past these spring waters played an essential and strategic role in supplying towns with potable water. Up to this day water is used by both the local population and tourists who thrust in its quality. A total of forty-four spring water and four artesian well water samples were collected at 26 points in different municipalities of the IQ in two different surveys, March and August 2015, wet and dry seasons, respectively. These water samples were studied for 38 physico-chemical parameters: turbidity (TB), electrical conductivity (EC), total dissolved solids (TDS), total hardness (TH), pH, Ca²⁺, Mg²⁺, Na⁺, K⁺, F^-, Cl^-, SO₄^2-, HCO₃^-, NH₄⁺, NO₃^-, NO₂^-, PO₄^-, SiO₂, Fe, Li, V, Cr, Cr (VI), Co, Ni, Cu, As, Ba, Al, Mn, Zn, Sb, Cd, Mo, Se, Tl, Hg and U, as well as thermotolerant coliforms (TC). The pH value of groundwater in the study area ranges from 3.8 to 7.0, indicating the acid nature of most of the spring water samples. In these samples, Ca²⁺ and Na⁺ are the major cations and HCO₃^- and NO₃^- the dominant anions. As expected, the trace metals presented the following decreasing concentrations: Fe> Ba> Al> Mn> Zn> Ni, since the IQ region is abundant in iron, aluminum and manganese minerals. The chemical relationships in Piper diagram identified mixed-bicarbonate, magnesium-bicarbonate and sodium-bicarbonate as the most prevalent water types. The Gibbs plots of data from the study area indicated that the chemical composition of most spring water samples was controlled primarily by rainfall dominance. Except for some springs, groundwater in the study area are inappropriate for drinking and domestic purposes but good for animal consumption, irrigation and recreation.

spring waters, Iron Quadrangle, Minas Gerais-Brazil, hydrochemical assessment, trace elements