A study of riverbank filtration effectiveness in the Kępa Bogumiłowicka well field, southern Poland

Southern Poland, Dunajec River catchment The study evaluated an eleven-year observation period of physicochemical parameters within a riverbank filtration (RBF) site located by the Dunajec River. A total of nine parameters (pH, electrical conductivity, sulphate, chloride, nitrate, manganese, water hardness, colour, turbidity) in both surface water and groundwater underwent statistical scrutiny. This analysis encompassed Spearman's correlation, linear mixed-effects models and hypothesis testing. This study revealed that the Dunajec River constitutes a major factor in forming the exploited groundwater physicochemical composition. Statistically significant differences between two rows of wells were found, implying a more substantial RBF impact on the row closer to the Dunajec. However, the river's influence on further wells was also highlighted. The RBF process in the study area was considered efficient since it maintained a stable groundwater physicochemical composition and provided sufficient water for exploitation over the years. Comprehending the interactions between the surface water and groundwater flow system is crucial to the well field sustainability, enabling water supply system optimisation and a more precise assessment of risks regarding groundwater contamination.