Abstract: A sludge settling basin in which a platform is movable over the basin and supports a siphon tube having a first portion extending to adjacent the floor of the basin, a second portion extending over the basin and a third portion extending downwardly into the channel of the side wall of the basin, the material in the channel being removed by a pump with a sufficient rate for the level of liquid in the channel always to be below the level of liquid in the settling basin, so that the sludge is siphoned from the basin into the channel and is removed by the pump.