Abstract: A water filtration system is provided by an upflow filter vessel containing a buoyant filter media in series with a downstream downflow filter vessel containing a nonbuoyant filter media. The buoyant media filter vessel and nonbuoyant media filter vessel comprise two compartments of a common tank, separated by a central wall. Water from the upflow filter vessel passes over the top of this wall, or through one or more openings in this wall, to the downflow filter vessel. A common waste trough extends from one end of the tank to the other. Weir plates are fastened to the upper edges of this trough such that the trough steps upwardly in elevation at the central wall. Waste materials from the upflow filter vessel pass over the lower of these weir plates and into the waste trough during cleaning of the buoyant media filter. In contrast, waste materials from the nonbuoyant media filter flow over the upper weir plates and into the trough during cleaning of this latter filter.

Abstract: A split flow water treatment plant includes a settling basin comprising a pair of banks of generally horizontally extending settling tubes and an inlet baffle comprising a plurality of parallel vertical perforated sheets upstream of and adjacent to each of the banks. An inclined diverting plate extends from the downstream end of the lowermost tube in the first of the banks to the upper upstream end of the inlet baffle adjacent the second bank. The distribution of flow between the banks may be regulated by an adjustable weir or by water level control.