Microbial, chemical and isotopic monitoring integrated approach to assess potential leachate contamination of groundwater in a landfill district in Apulia region (Italy).

Abstract Landfill sites are a major concern for soil and groundwater pollution in the disposal area. The impact of accidental spill of leachate through the soil and consequential contamination of the groundwater can seriously threaten human health and the environment. Given the impact of other anthropic activities (i.e., agriculture, cattle farming etc.) coexisting in the same site, the perturbation of groundwater environment may be due my multiple factors. Therefore, it is a challenging issue to correctly establish the pollution source of an aquifer where landfill is not isolated from other anthropic land uses. The present study aimed to realize an integrated environmental monitoring that included microbiological and chemical methods to evaluate potential groundwater pollution in a landfill district in the south of Italy. Conventional (microbial plate count, physical-chemical analyses) and advanced methods (PCR-ARISA, isotope analysis) were included in the study, to characterize both the groundwater aquifer in nine sites surrounding the landfill district and the leachate of the active landfills. By the integration of the acquired data, it was possible to reconstruct the scenario by which agriculture and other human activities, together with seawater intrusion in the karst aquifer, were the main drivers of altered groundwater features in the monitored site. It was possible to exclude any contribution of the landfill leachate to the groundwater environment perturbations.