Containment wall installation process and apparatus

A method for installing a groundwater containment system utilizing a powered trenching apparatus, the apparatus having a main body defining front and rear ends;

• a boom coupled to the rear end thereof;
• a trenching tool coupled to the boom for displacing soil to define a trench;
• frame structure mounted with respect to the boom rearwardly of the trenching tool, said frame structure including opposing sidewalls defining a space therebetween, said space being separated into at least first and second adjacent compartments, each said compartment having an inlet opening and an exit opening, the method comprising the steps of:
• advancing the trenching apparatus along the ground such that the trenching tool creates a single trench, with said frame structure advancing within the trench as the trench is being excavated,
• feeding filter material into said second compartment through the inlet opening thereof,
• inserting at least one impermeable wall panel into said first compartment through the inlet opening thereof,
• wherein during the advancing step, said at least one wall panel passes through the exit opening of the first compartment and at least some of the filter material passes through the exit opening of the second compartment in such a manner that said at least one wall panel is disposed within the trench between a wall of the trench and filter material exiting said second compartment.