Natural background levels (NBLs) for targeted chemical elements characterize a specific groundwater body, the knowledge of which represents a fundamental information for environmental agencies responsible for the protection, management, and remediation of territory. The large number of areas subject to strong anthropogenic pressures of a different nature and magnitude makes the job of control authorities particularly difficult. The process to distinguish effective anthropogenic contamination from natural conditions and to define realistic environmental clean-up goals goes through the computation of several mutually dependent statistical methods, some of which have non-trivial resolution and interpretation. In this study, we presented a new tool designed to drive those working in the sector into an articulated path towards NBL assessment. The application software was developed in order to read environmental input data provided by a user-friendly web-based geographic information system (GIS) and to return the NBL estimate of a given chemical element following a wizard that allows for the implementation of two methodologies, i.e., component separation or pre-selection. The project was born from a collaboration between the Department of Environmental Engineering of the University of Calabria and the Department of Environmental Policies of the Calabria Region. The software was used to estimate NBLs in selected chemical species at potentially contaminated industrial sites located in Lamezia Terme, Italy. In the future, the developed calculation program will be the official evaluation tool of the Calabria Region for identifying groundwater thresholds.

The use of isotopic geochemistry for hydrogeological studies is growing internationally. The use of isotopic geochemistry methodologies on hydrogeological survey data, integrated with the use natural tracers, is helpful when defining the hydrogeological model of the aquifer. In particular, the use of radioisotope concentration measurements as natural tracers and the detection of the temperature, redox potential and dissolved oxygen in groundwater in the field provide information on underground water circulation, which is useful for identifying recharge areas and groundwater drainage. Variations in these parameters in the aquifer allow for information about its hydrodynamics to be obtained. The application of this method in a sample area showed how the uranium and radon concentrations, temperature, redox potential and dissolved oxygen vary in the different sectors of the aquifer, depending on water mobility. This information, integrated with the results of a hydrogeological survey of the static levels, distinguished the recharge and drainage areas of the aquifer and the preferential directions in terms of water flow and allowed for information on the mobility of the aquifer in the various sectors to be obtained. The method presented in this paper was tested in a larger hydrogeological study in the southern sector of the shallow aquifer of the S. Eufemia Lamezia plain (Calabria, Italy).

In Calabria, there are few works of quantitative hydrogeology. Therefore, the present study aims to provide a contribution to the hydrogeological knowledge of the region and, in particular, of the shallow aquifer of the S. E. Lamezia plain, characterized by a multi-layer aquifer. The study area is located in the Tyrrhenian sector of the “Graben of Catanzaro, an important tectonic structure in the wider context of the Calabrian Peloritano Arc. The acquisition of new lithostratigraphic and hydrogeological data, related to drillings for water research, has allowed expanding the knowledge of the phreatic aquifer of S. E. Lamezia plain. In the study area, there is a high number of abusive wells without data, not declared and are made without a basic hydrogeological study. Therefore, they are free of flow rate tests and information about the drilling depth, stratigraphy and construction methods. However, a certain numbers of wells is authorized and the available data are: Stratigraphy, static and dynamic level, critical flow rare (Qc) and, in some cases, also the specific lowering (Δs). Therefore with these data, using empirical formulas, a quick analysis of the hydrogeological parameters characteristic of the aquifer it was done. Moreover, interpolating the stratigraphic data with a geostatistic method the map of the clay substrate was returned. In particular, the Transmissivity [T] and the Storage coefficient [S] were calculate with empirical formulas using well data. From the Transmissivity. the Hydraulic conductivity [K] is derived. The hydraulic gradient from the piezometric map graphically is calculated. The thickness of the saturated layer (b) of the aquifer was obtained directly from the stratigraphy of the wells surveyed or, in those cases in which stratigraphy was not known, from the differences between the values obtained from the isopiezometric map and the map of the clay substrate. In conclusion, this study, with the implementation of the clay substrate map and a quick analysis of the main hydrodynamic parameters, aims to provide a contribution to the definition of the hydrogeological model of the shallow aquifer of the Plain that represents a fundamental tool for the protection and the correct management of the water resource.