Pacheco, G., Costa, A.B. da, Silveira, E.O., Deprá, B. and Lobo, E.A. 2016. Calibration of a groundwater quality index (IQNAS) for the region of vale do Rio Pardo, RS, Brazil: new technological tool for environmen-tal monitoring. Águas Subterrâneas. 30, 3 (Nov. 2016), 440–454. DOI:https://doi.org/10.14295/ras.v30i3.28616.