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 to
numerous investigations linked to the presence of abandoned
mines and related acid mine drainages. This study aims to achieve
new insights into water circulation in carbonate aquifers feeding
three of the major springs of the area (Moresco springs: VSMOA,
VSMOS, VSMOG). VSMOA and VSMOS show evidences of hydraulic
connection with Baccatoio stream, contaminated by acid mine
drainages. The study focused on springs chemical and isotopic
variations induced by a rainfall event. Some general conclusions can
be drown: (i) the hydraulic connection between Baccatoio stream and
VSMOA-VSMOS seems to be confirmed; (ii) during rainfall events,
infiltrated rainwater seem to directly contribute to the perturbation
of VSMOA-VSMOS; (iii) different flow fractions feeding VSMOAVSMOS
after rainfall pulse were quantified; (iv) VSMOG did not show
any perturbation linked to the rainfall.