ABSTRACT
Studies on arsenic (As) occurrence in groundwaters in Osijek-Baranja county have been reported. Even after water treatment of groundwater, As concentrations are above 10 µg/L, which is maximum contaminant level (MCL). To reduce As concentration, groundwater is mixed with surface water from the river Drava. In this study As concentrations were monitored from February to October of 2019, along with concentrations of disinfection byproducts (DBPs) to see if there is some correlation between these parameters. GIS was used to create a map with a sampling points, and software Statistica was used for descriptive statistics and to calculate Spearman's correlation coefficients. Average As concentration in the water distribution system (WDS) was 22.1 µg/L, with a range from 5.3 to 34.6 µg/L. Average concentrations for THM and HAA were 8.4 µg/L and 4.2 µg/L. As concentrations statistically significantly correlate with THMs; BDCM (r = −0.28, p<0.05), DBCM (r = −0.29, p<0.05) and TBM (r = −0.34, p<0.05) and with one HAA, DBAA (r = −0.25, p<0.05).
