Analysis of the potential contamination risk of groundwater resources circulating in areas with anthropogenic activities

Abstract. The area investigated is located in the province of Brindisi (Italy). It is a generally flat area separated from the nearby carbonatic plateau of the Murgia by quite indistinct and high fault scarps. As regards the geological features, carbonatic basement rocks and post-cretaceous terrains made up of calabrian calcarenites and middle-upper Pleistocenic marine terraced deposits can be distinguished.

In the examined area there are two different hydrogeological environments. The first is represented by deep groundwater, the main groundwater resource in Apulia.

The second hydrogeological environment, now of lesser importance than the deep aquifer in terms of size and use, is made up of some small shallow groundwater systems situated in post-calabrian sands and located in the eastern area.

During some sampling cycles carried out in the studied area, water was withdrawn from both the deep aquifer and from the shallow groundwater. For every sample, the necessary parameters were determined for the physical and chemical characterisation of two different hydrogeological environments. Moreover, some chemical parameters indicating anthropogenic activities were determined.

Analysis of the aerial distribution of the measured parameters has shown some main areas subject to different conditions of contamination risk, in accordance with the hydrogeological and geological features of the investigated area.

In the south-eastern part of the investigated area, the important action performed by the surface aquifer for protecting the deep groundwater from contamination of anthropogenic origin is clear.

On the other hand, in the shallow groundwater, areas of nitrate and nitrite contamination have been identified, which result from the extensive use of fertilizers.