Hydrodynamic and geochemical behavior of a karst aquifer system exposed to contamination: analysis of the response of the Moresco Springs (Apuan Alps, Italy) to rainfall.

The Baccatoio Stream basin (Apuan Alps) was subjected tonumerous investigations linked to the presence of abandonedmines and related acid mine drainages. This study aims to achievenew insights into water circulation in carbonate aquifers feedingthree of the major springs of the area (Moresco springs: VSMOA,VSMOS, VSMOG). VSMOA and VSMOS show evidences of hydraulicconnection with Baccatoio stream, contaminated by acid minedrainages. The study focused on springs chemical and isotopicvariations induced by a rainfall event. Some general conclusions canbe drown: (i) the hydraulic connection between Baccatoio stream andVSMOA-VSMOS seems to be confirmed; (ii) during rainfall events,infiltrated rainwater seem to directly contribute to the perturbationof VSMOA-VSMOS; (iii) different flow fractions feeding VSMOAVSMOSafter rainfall pulse were quantified; (iv) VSMOG did not showany perturbation linked to the rainfall.