Assessing background values of chloride, sulfate and fluoride in groundwater: A geochemical-statistical approach at a regional scale

The results of this study indicate that the integration of hierarchical clustering analysis with the geochemical characteristics of groundwater, also taking into account the geological context, allow the repartition of groundwater samples in distinct hydrogeochemical groups, which in turn allow to calculate the background ranges and reliable threshold values in groundwater. This approach can be applied to assess the background concentrations of chemical parameters at a regional scale when a large dataset is available.