Abstract: An underdrain filter block for use in draining and backwashing a filtering media in a filter bed includes a top wall, a pair of side walls extending from the top wall, and a bottom wall extending between the pair of side walls. The top wall, the pair of side walls, and the bottom wall define an upper portion and a lower portion. The lower portion includes a grout chamber having a plurality of openings defined by at least one of the bottom wall and the pair of side walls.

Abstract: A media retainer assembly for retaining filter media in a filter assembly includes a top plate for supporting the filter media, the top plate having a top surface, a bottom surface and a plurality of openings extending therethrough; a bottom plate having a top surface and a plurality of openings extending therethrough; and scouring media, the scouring media being adapted to abrade the surfaces of the top and bottom plates. The top plate is connected to the bottom plate such that the top surface of the bottom plate is spaced from the bottom surface of the top plate to define at least one chamber between the top plate and the bottom plate. The top surface of the top plate is in fluid communication with the chamber via the openings in the top plate. The scouring media is supported by the bottom plate within the at least one chamber.

Abstract: The present invention is related to a method and system for cleaning a media support structure in a filter cell in a liquid filter system, wherein a cleaning solution does not significantly enter a filter media zone. The method comprises supplying a cleaning solution to a filter cell to a level sufficient to submerge the media support structure, but not to significantly enter the filter media zone. Additionally, the cleaning solution level is monitored to ensure the cleaning solution does not significantly enter the filter media zone. Alternatively, the cleaning solution may be continuously recirculated and reintroduced to the filter cell during the cleaning operation.

Abstract: An adjustable anchor rod arrangement for use with an underdrain system that includes the a pair of spaced apart legs and an elongated member adjustably attached to the legs, wherein the legs are adjustable along a longitudinal axis of the elongated member and the elongated member is adjustable along a longitudinal axis of the legs.