Point and nonpoint pollution and restoring groundwater quality in Italy: 30 years of experience

In Italy, a significant portion of the drinking water supply is provided by groundwater, hence also the importance given to its protection. For nonpoint pollutants, the paper describes the experimental approach (field trials) and cartographic materials (vulnerability maps) used to assess the nitrogen dynamics and the consequent presence of nitrates in groundwater. In the high vulnerability areas, there are limitations on the use of agricultural fertilizers, while in urban areas, various interventions on water discharges must be undertaken. Little information is available from the monitoring network with regard to emerging pollutants. For point pollutants in contaminated sites, an estimate is given of the distribution of the most frequently found substances; after a detailed description of these substances, possible remediation technologies are discussed. Despite the recovery of the mass of pollutants even as much as 90–99%, the cleanup values (expected concentrations expressed as µg/L) established by national legislation have not been achieved. It can be stated that the scientific community is considering the new paradigm expressed by the “order of magnitude of the flow of pollutant mass” to replace the old paradigm consisting in the “limit value of final concentrations”.