Quality of water in two areas affected by past mining activities in alpine context

Abstract

Abandoned mines can pose serious pressure on local water sources. Analyses of the possible water related environmental problems connected to past mining activities was performed in two mining areas, Campello Monti and Gorno in NW Italy. To study impacts on local water sources water sampling campaigns and analyses were performed. The samples were analyzed to measure alkalinity, electrical conductivity, pH, chemical elements: Hg, Tl, Cd, Cr (total), Cr (VI), Ag, As, Pb, Se, Ni, Co, Mn, Al, Fe, Cu, Zn, B and other analytes: CN-, Fl-, Mg2+, Na+, SO4 2-, NO3-,Cl-.The water samples collected in Campello Monti area showed nickel contamination. The water samples collected at Gorno showed no contamination. Both Gorno and Campello Monti are two areas that were affected by intense mining activity in past. The absence of contamination in water (groundwater and rivers) in Gorno compared to Campello Monti may be due to several concomitant factors apartfrom the different geological context: in Gorno the higher pH of groundwater, which facilitates the precipitation of heavy metals and the increased flow velocity in the karst limestone rocks.