Hydrostructural setting of Riardo Plain: effects on Ferrarelle mineral water type

The exploitation of groundwater resources must always keep in account the geology and hydrogeological settings of the catchment basin for the sustainability of withdrawals, in order not to overexploit the aquifer. Especially, in the case of mineral water extraction, even more attention should be paid to understand what are the water-rock-gases interaction mechanisms, which allow obtaining a specific water chemistry. The case of Ferrarelle mineral water (western sector of Riardo Plain, Caserta) is particularly complex. Through the acquisition of a great amount of former geological and hydrogeological data and by new hydrogeological surveys, it has been possible to distinguish the aquifer levels, distinguishing four circulations over the Roccamonfina Volcano and in the Riardo Plain. The presence of volcanic and volcaniclastic deposits deriving from the Roccamonfina Volcano which cover a highlytectonized carbonate bedrock, allows the formation of two aquifers in hydraulic continuity. This mixing between the two aquifers allows, with the ascent of deep CO₂ through faults in the carbonate bedrock, the formation of the typical chemical composition of the mineral water Ferrarelle. In the eastern sector of the plain, it is possible to distinguish the volcanic aquifer from the carbonate one, probably due to the presence of low permeability deposits.