Spatial and temporal trend of groundwater contamination from terbuthylazine and desethyl-terbuthylazine in the Lombardy Region (Italy)

In the last few years, several monitoring programs were established as an effect of the EU Directives which included requirements for monitoring the quality of water resources (drinking water, groundwater and surface water). Plant Protection Products (PPPs) are an obvious target for monitoring activities, since they are directly released into the environment. In Italy, the National Environmental Protection Agency (ISPRA) has recently published several reports containing the results of the National Plans for Control of Environmental Effects of PPPs. These documents contain the collection of monitoring data related to the presence of PPP residues in surface and groundwater systems. In this paper, these results (monitoring campaigns from 2005 to 2009) were analysed. Particularly, the attention was focused on the concentration levels of terbuthylazine (TBZ) and its metabolite desethyl-terbuthylazine (DTZ) detected in the groundwater systems of the Lombardia Region (Northern Italy). The analysis allowed us to identify the spatial and temporal trends of contamination of both substances. Furthermore the DTZ/TBZ ratio was calculated in order to recognize point and non-point sources of contamination.