Groundwater geochemistry of Su Bentu cave (Sardinia, Italy)

The karst aquifer of Supramonte (Central East Sardinia) consists of an underground cave network that reaches a known cave development of more than 50 km over an altitudinal difference of about 1000 m. Its groundwater circulation is believed to occur through dominant conduits that convey their water flow from the distal recharge area in the South to the main outlets in the North (Su Gologone, Su Tippari and San Pantaleo springs) forming an interconnected system (Sanna & Cabras, 2015). The Su Gologone spring, the only accessible one since the other two are submerged by the artificial lake on the River Cedrino (De Waele, 2008), supplies drinking water to the local population. As required by the Water Framework Directive (2000/60/EC) the monitoring of physico-chemical parameters of drinkable water sources is essential to ensure groundwater quality as a basis for the sustainable management. Su Bentu cave represents a segment of this karst aquifer and the accessible known underground drainage nearest to the exploited spring. The geochemical monitoring of its groundwater contributes to assess the quality status of drinking water.