An improved liquid run-off disposal system is described having an infiltration chamber (72) with first and second sidewalls (74). In cross-sectional view the first and second sidewalls (74) each include an inner surface 76 and outer surface (78), and each sidewall (74) includes a plurality of integrated louvre- shaped apertures (80). In cross-sectional view each louvre-shaped aperture (80) includes an upper surface (82) and a lower surface (84) which are angled upwards from the outer surface (78) and protrude inwards from the inner surface (76) into the interior of the infiltration chamber (72). The upper and lower surfaces (82, 84) comprise a plurality of angled sections, the angled sections being arranged so as to form a substantially vertical flow path through a portion of the aperture (80). The angled sections of the upper and lower surfaces (82, 84) are arranged at an angle and of a length so as to substantially overlap when viewed in a horizontal direction. The overlapping region "Y1" ensures that the a