Assessment of river water infiltration conditions based on both chloride mass-balance and hydrogeological setting: the Krajkowo riverbank filtration site (Poland)

Abstract In the present work measurements of chloride concentrations were used to assess variability infiltration conditions and contributions surface water local groundwater discharge wells at Krajkowo riverbank filtration site (western Poland). Tests performed on samples from 26 located in a well gallery close River Warta. Due higher river comparison with groundwater, significant differences individual noted. particular, lower 11 recorded, which can be linked occurrence low-permeability deposits superficial zone; locally degree riverbed sediment clogging highly convex meandering zone, where strong erosion occurred, turn led increased clogging; more intensive inflow into valley due smaller entering Warta valley, as unfavourable for part aquifer greater thickness. Differences observed also quantify approximately contribution production. The average recharge entire was estimated 59.8%.