Abstract: A method of installing a groundwater containment system is provided utilizing a powered trenching apparatus. The apparatus includes a boom at an end thereof; a trenching tool coupled to the boom; and frame structure mounted with respect to the boom. The frame structure is separated into at least first and second adjacent compartments. Each compartment has an inlet opening and an exit opening. The method includes advancing the trenching apparatus to create a single trench with the frame structure being disposed within the trench. Filter material is fed through the inlet opening of the second compartment. A first, impermeable wall panel is inserted through the inlet opening of the first compartment.