Containment using a soil-bentonite mixture (SBM) cut-off wall is a valid method to prevent the contaminants in soil from migrating in the aquifer. A new construction technique for the SBM vertical cut-off wall has been developed by employing the trench cutting and re-mixing deep wall method to achieve excellent homogeneity of the wall. This paper addresses this construction method and the laboratory testing results on the hydraulic barrier performance of SBM focusing on its chemical compatibility. Hydraulic conductivity values were measured for SBM specimens, which were processed from various types of soil with different concentrations of divalent cation (Ca2+) in the permeant or in the pore water of original soil. For the Ca2+ concentrations lower than 0.01 M in soil pore water, there is no significant effect on the hydraulic conductivity of SBM. For the higher Ca2+ concentrations, more than one order of magnitude higher hydraulic conductivity values were observed. The correlation between the hydraulic conductivity and the void ratio change in SBM specimen implies that the void ratio change could be a good indicator of the hydraulic conductivity for different types of soil. Copyright ASCE 2008.