TITLE:
An Integrated Hydrogeological and Hydrogeochemical Approach for Distinguishing Point-Source Contamination from Natural Background Levels at a Landfill Site: The La Silva Case, Cassano Allo Ionio (Southern Italy)
AUTHORS:
Giulio Riga, Vincenzo De Matteis, Francesco Petrone
KEYWORDS:
Groundwater, Landfill, Iron, Manganese, Natural Background Levels, Redox Conditions, Hydrogeochemistry, Site-Specific Conceptual Model
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.14 No.10,
October
30,
2026
ABSTRACT: The report presents an integrated hydrogeological, geochemical, and geophysical investigation of a municipal solid waste landfill area located in Cassano allo Ionio (CS), Southern Italy. The study aimed to characterize the local subsurface, assess groundwater quality, and determine whether the elevated concentrations of iron (Fe) and manganese (Mn) are attributable to landfill-related contamination or to naturally occurring geogenic processes. The investigation identified a deep aquifer hosted within Pliocene conglomeratic deposits, characterized by low intrinsic vulnerability and groundwater flow predominantly toward the southeast, although locally complex piezometric conditions were observed. Although iron and manganese concentrations exceeded regulatory contamination thresholds in several monitoring wells, their spatial distribution, the prevailing redox conditions, their occurrence at upgradient locations, and comparison with surface waters and a nearby agricultural well indicate that these anomalies are more consistent with natural water-rock interactions and reductive dissolution processes within sandy-conglomeratic layers containing silty-clayey lenses than with the presence of a landfill-derived leachate plume. Geophysical investigations also contributed to delineating the geometry of the landfill and estimating the depth of the waste deposits, thereby supporting a more comprehensive characterization of the site.