the present study aims to quantify basic parameters for the transport and retention of metal ions in contention barrier systems. a synthetic leachate with ph 1 and known concentrations of ions chromium, cadmium and copper was used. sorption and molecular diffusion experiments were carried out in compacted soil, soil mixture with 10% sodium bentonite and compacted soil overlaid with geomembrane. it was implemented in the program mphmtp (multi phase heat and mass transfer program) where the equations describe ion behavior under adjusted parameters obtained from sorption and diffusion tests. the geomembrane’s presence minimizes ion migration through a diffusive process, and eliminates the need for the soil sorption capacity. but the soil with the bentonite option proved to be the most predominant specific alternative due to its cadmium sorption capacity.