Hydrogeochemical characteristics of a stratified aquifer and groundwater quality degradation (Sila Massif, Italy)

Hydrogeochemical surveys were carried out in eastern Calabria (Italy) for recognizing the groundwater flow domain, assessing the utilization level, and characterizing the degradation risks. Physical-chemical parameters of groundwater and surface water were determined. Waters draining crystalline and metamorphic rocks have Mg-HCO3 to Na-Ca-HCO3 compositions and low salinity (<0.20 g/L), whereas waters from sedimentary environments belong to the Ca-HCO3 facies and have higher salinity (0.20 to 0.76 g/L). Waters interacting with evaporite formations show a dominant Ca-SO4 composition, and high salinity (up to 2.9 g/L). The concentrations of toxic components are usually low, but in some samples nitrates and arsenic exceed the drinking limit. It is shown that quality degradation is due to anthropogenic activities, mis-use of fertilisers, or discharge of untreated urban wastes.