Soils in the northern part of Belgium are contaminated with Cd, due to the activity of zinc ore smelters in the past. The contamination of ground and surface water is limited at the moment. However, leaching of Cd to the groundwater can have serious consequences for the environment in the future. There's insufficient knowledge about the risk of Cd leaching. To predict the transport of Cd, following aspects must be further investigated: factors governing the soil-soil solution partition (pH, organic matter content, Ca-concentration,...), fixation of Cd, kinetics of the sorption reactions and influence of field heterogeneity on the transport. With bath experiments and soil column experiments, there will be tried to get clearness about these aspects. The results will be used to predict the cadmium transport in a trial field.