Nitrate pollution in different hydrogeological zones of the groundwater flow system in the volcanic structure of Mt. Vulture (Basilicata, Southern Italy).

A survey on groundwater quality of Mt. Vulture volcanic structure, undertaken from 2003 to 2005, indicates that nitrate pollution is a serious problem affecting the water resources. The Mt. Vulture, inactive volcano, is located on the northern border of the Basilicata region (southern Italy) and it formed in an area of strong tectonic instability. The analysis of geological, stratigraphical, hydrogeological and hydrochemical data contributes to delineate the groundwater hydrodynamics of Mt. Vulture that represents a huge aquifer characterized by precious mineral waters. The rapid expansion of intensive agricultural activities has greatly increased the use of nitrogen (N) fertilizer. In this study has been reconstructed the map of the nitrate concentrations in groundwater. The comparison between the winter-summer nitrate data and the intrinsic pollution vulnerability map (Spilotro et al., 2004) evidences the determining role in different hydrogeological zones of the groundwater flow system in the seasonal variations of the concentrations and in the total dilution of the pollutant.