The industrial and petrochemical complex of Bahia Blanca was implanted on an artificial compacted landfill that in some sites complemented itself with dredging material. This caused a modification in the natural system´s hydrodynamics, affecting directly the rates of recharge of the phreatic aquifer. This study aims to quantify the water excesses of soil by calculating the hydrological balance, applying the Balshort V.3 and Hydrus 1D codes. The quantification of recharge rates will be fundamental to determine the transport velocity of possible pollutants. The obtained results allow estimating the range of recharge rates as 12% to 18% of rainfall under normal conditions of raining (500 – 575 mm/year). The average water excess, without considering artificial hydraulic load, of 44 mm/year is consistent with a transport time for unreactive solute of 10,2 years, representing in medium term, a potential danger for the phreatic aquifer.