Abstract: A method and apparatus for constructing a slurry wall in a trench utilizing a trenching apparatus equipped with slurry barriers behind the digging chain adapted to slidingly engage the opposite side walls of the trench from the ground level to the bottom of the trench and a trailing unit also behind the trencher straddling the trench and comprising plows near the point at which the digging chain deposits excavated soil at the ground level and a slurry injector for introducing slurry into the trench behind the slurry barriers. In a preferred embodiment, actuators are employed to shift the slurry barriers from a retracted position into an operative position.