High pressure artesian wells to tap Torbido spring (Italy)

Abstract

Torbido Spring is located at the foot of Mount Sirino (Basilicata, Italy). From the bottom upwards the geological formations include: Flinty Limestones with high secondary permeability, forming the spring aquifer; Siliceous Schists consisting of radiolarites and multicoloured jaspers; and Galestrino Flysch, formed of argillites and marls. The Spring is singular in that the artesian waters from the limestones which are at a depth of 80 m here, come to the surface because of the marked fissuring of the Siliceous Schists. The headworks consist of a system of unpumped wells. The groundwaters are intercepted before they leak away in the detrital surface cover and before they lose their hydrostatic head (more than 4 bar above ground level). The maximum discharge which can be abstracted and handled by the wellfield and appurtenant works is around 300 l/s. This permits peak demand to be met without any waste of resources and guarantees the annual hydrologic balance between recharge and discharge. These objectives are attained by continuous monitoring of the significant hydrogeological and hydraulic parameters.