A 20-year chronological record of the flow of water and anions, along 27 m, in the unsaturated zone of a phreatic aquifer was reconstructed. Water was traced according to its tritium content, using the difference between the environmental tritium content of rain and irrigation water. Anions were traced using data about their sequential input to the overlying cultivated field and their concentration in the profile. Evidences of anion exlcusion were found along a 10-m thick clay loam layer. The vertical velocities of water molecules and anions (SO2-4 and Cl-) were calculated to be 0.7 ± 0.05 and 1.35 ± 0.05 m yr-, respectively. The average thickness of the water films and the equivalent distance of exclusion, at a 15% gravimetric water content, were 25 and 12 Å, respectively. These field data fit and support the theoretical relationship between the water film thickness and the relative exclusion concentration proposed by Bresler (1973).