A series of 2-D tank experiments were conducted to investigate the impact of non-uniform organic-liquid distribution, type of porous media, and methyl-beta-cyclodextrin (MCD) flooding on the relationship between source zone mass removal and mass-flux reduction for heterogeneous porous media. Trichloroethene was used as the model organic liquid, and MCD was used as enhanced flushing reagent. The results were also compared to those of water-flood control experiments. The results showed that the representative heterogeneous system exhibited specific non-ideal multi-step mass-flux reduction/mass removal behavior depended upon different porous media configurations. This non-ideal behavior was observed for both the water-flood and MCD flooding experiments. For all cases, early stage of trichloroethene mass removal was controlled by greater relative hydraulically accessibility of the dense non-aqueous-phase liquid (DNAPL) source distributed within the porous media matrix compared to later stage removal which was controlled by poorly hydraulically accessible mass associated with higher saturated or pooled DNAPL source zones. The results of this study significantly revealed the impact of non-uniform organic liquid distribution, flow-field heterogeneity, type of porous media, and the concentration of MCD on mass removal and mass-flux reduction behavior.