Experimental results of sorption/desorption obtained from a gravimetric method are presented for a polypropylene geomembrane with various organic liquids at 25, 50, and 70 degrees C. The sorption data have been fitted to an Arrhenius relationship to obtain the heat of sorption. The sorption/desorption data have been analyzed using an empirical equation. The swelling of the PP geomembrane has also been studied for the chosen liquids. Experimental results and the derived quantities have been discussed to study the chemical resistivity of the geomembrane.