Abstract: A soil retention wall system 10 includes a plurality of vertical piles 12 placed in spaced succession. A plurality of hollow polymeric lagging members 14 are stacked transversely relative to, and spanning between, successive piles to form the wall. Each lagging member is formed from a shell having a major wall 106 defining top and bottom surfaces 28 and 30, and first and second endwalls 36 and 38 each adapted to be engagable with an adjacent pile. In a preferred embodiment, the shell 24 is of unitary, one-piece construction.