Development of a Water Quality Index (WQI) for public supply in the Vale do Rio Pardo region, RS, Brazil

This research developed a Water Quality Index (WQI) for public supply in the Vale do Rio Pardo Region, RS, Brazil (WQI-VRP), from database of 13th Regional Health Coordination, totaling 1175 samples. A filtration process resulted 285 samples with variables free residual chlorine, turbidity, apparent color, pH, fluoride, total coliforms and Escherichia coli. For water consumption purposes, by Sanitation Company Goiás, Brazil, was used. multivariate calibration weights importance parameters included original index performed, resulting WQI-VRP. Comparing medians two indexes, it found that there were significant differences (p<0.05), qualifying WQI-VRP as more restrictive. The results indicated 89.8% classified non-compliant WQI-VRP, while 10.2% compliant Of analyzed, 72 12 coliform, 5 E. coli, 2 200 fluoride 26 below or above minimum maximum values required Brazilian legislation. pH correspond to critical study region, they showed greatest increases relative when comparing calibrated one. These confirm use an efficient tool assess quality drinking subtropical temperate lotic systems.