Patent ID: 7285211

Claim:
A retention treatment basin that handles an influent of combined wastewater and sewer overflows, the influent including floatable and settlable solids, the retention basin including a floor, the retention basin having: one or more influent channels that duct the influent into the retention basin, a weir extending upwardly from the floor, over which the influent may flow; a cell that receives the influent passing over the weir, at least some of the settlable solids being retained in the cell; a screen-supporting baffle extending downwardly from the ceiling so that no influent may pass between the baffle and the ceiling, the baffle retaining at least some of the floatable solids in the cell, part of the influent passing under the baffle; one or more up-flow screen systems extending generally horizontally from the screen-supporting baffle and being rigidly supported thereby that are pervious to fluids, the one or more up-flow screen systems receiving the influent and arresting movement of floatable solids therethrough, thereby creating a floatable-solids depleted effluent; and a backwash delivery system situated above the one or more up-flow screen systems, the backwash delivery system irrigating an upper surface of the one or more up-flow screen systems by a downwardly directed flow of fluid so that solids retained by a lower surface of the one or more screen systems are flushed away therefrom.