In order to predict the dissolution of multi component mixtures in the subsurface, a mathematical model is developed. The model contains essential processes such as dissolution, dilution, mass transfer and multi component interactions. Experimental data obtained in present work is simulated by using this model. Experimental studies performed with the mixture of Trichloroethylene (TCE) and Perchloroethylene (PCE) in five columns shows that added whole mixture does not participate to dissolution process. Some amount of the mixture subsides to the underside of the column and a pool of the mixture is formed. The pool formation causes lower dissolution rates because of lower contact opportunity with water. Residual saturation values relatively to the void volume are obtained as 5.08% for TCE and 2.43% for PCE, volumetrically. In the simulation of experimental data, these poolings are taken into account by the subtraction of the pooled amount from total mixture amount, when there is not enough hydraulic hardening to get contact with whole mixture due to insufficient present residual content.