A system includes a sand filter disposed within a tank. A pipe connected to the tank is configured to flow fluid in or out of the tank. The system includes a valve configured to selectively allow fluid to flow through the pipe and a flowmeter configured to measure a flow rate of fluid through the pipe. An automatic control unit includes one or more processors and a non-transitory computer readable medium storing instructions executable by the one or more processors to perform operations including determining a debris accumulation status for the sand filter based in part on flow measurements from the flowmeter, and determining a failure status of the valve based in part on flow measurements from the flowmeter.

An apparatus for use in a filter system for filtering water or wastewater. The apparatus preferably includes at least one underdrain lateral having at least an inner chamber, a first outer chamber and a second outer chamber. The first outer chamber and the second outer chamber are preferably in fluid communication with the inner chamber. The inner chamber, the first outer chamber and the second outer chamber are preferably formed by an inner liner and an outer liner. The outer liner is a separate piece from the inner liner and surrounds the inner liner. The inner chamber is preferably configured to simultaneously receive a liquid and a gas during a washing procedure including simultaneous use of a liquid and gas to clean a filter bed to create a liquid and gas interface in the inner chamber.

A filter media retainer has a plate having a first end wall, a second end wall, and a pair of longitudinal sidewalls connected to opposing sides of the first end wall and the second end wall. The plate has a top surface opposite a bottom surface. A plurality of hopper-shaped compartments are formed on the top surface and have a first sloped wall and a second sloped wall angled toward the first sloped wall in a direction from the top surface toward the bottom surface. The plate further has a top sidewall on the top surface of the plate separating adjacent hopper-shaped compartments from each other. The plate further has at least one first slot extending through at least one of the first sloped wall and the second sloped wall, and at least one second slot extending through the top sidewall.

An underdrain block for filtering water includes a top wall, a bottom wall, and two side walls connecting the top wall to the bottom wall to define an internal chamber. The bottom wall contains a plurality of orifices that allow liquid and solid materials to enter and exit the internal chamber. An underdrain filtering system can be formed by securing an underdrain lateral, which is formed from one or a plurality of underdrain blocks, to a filter floor. Also included is a method of preparing an underdrain lateral for providing even distribution of backwash water along the underdrain lateral and a method of validating even distribution of backwash water across an underdrain lateral.

The present disclosure a mechanical filter element (2) for forming a static filter pack (11) to perform mechanical filtration of a liquid. The mechanical filter element (1) has one or more filter cell (19). The present disclosure also relates to a mechanical filter apparatus (1) having a filter chamber (10) containing a plurality of mechanical filter elements (2) for forming the static filter pack (11) to perform mechanical filtration of a liquid. The mechanical filter apparatus (1) is configured to generate a flow of the liquid through the mechanical filter elements (2) during filtration to form the static filter pack (11). Furthermore, the present disclosure relates to a method of mechanically filtering a liquid. A plurality of mechanical filter elements (2) each comprising one or more filter cell (19) are disposed in a filter chamber (10). During filtration, the liquid flows through the filter chamber (10) to establish a static filter pack (11) of said mechanical filter elements (2) to mechanically filter the liquid.

Devices and methods associated therewith for facilitating movement, removal and/or installation of components from treatment units (e.g., water treatment units and wastewater treatment units). The treatment unit can take the form of a granular media filter (e.g., upflow filter, downflow filter or bi-flow filter) or a sludge collection basin. One preferred device is one or more floats facilitating safe removal of components of a treatment unit. The float(s) can be operably associated with an air scour system of a water filter to remove the air scour system from a granular media filter bed. The float(s) can be operably associated with a collection grid of a sludge collection container facilitating safe removal of the collection grid from the sludge collection container. Another preferred device is a flexible piping/conduit operably connected to a pressurized air source and an air scour system to assist in removal/installation of the air scour system.

An underdrain apparatus and a method for manufacturing such apparatus are provided. The underdrain apparatus can be extruded in long sections as a unitary part. The underdrain apparatus may be extruded in various sizes, shapes, and materials. Further, the underdrain apparatus may include a passageway for transporting water to and from the filter media and/or air to the filter media. In some embodiments, apertures are formed in the underdrain apparatus during an extrusion process to provide a path between the passageway and the filter media.

A method of distributing gas and liquid through an underdrain system includes: a) positioning an underdrain system on a filter floor, the underdrain system comprising at least one underdrain block and filter media positioned on top of the underdrain block; b) distributing gas sufficiently evenly through the underdrain system at a rate of less than 2 scfm/ft.sup.2 by distributing a liquid at a rate of less than 2 gpm/ft.sup.2 concurrently with the gas; c) increasing the distribution rate of the liquid, or increasing the distribution rate of the liquid and the distribution rate of the gas; d) stopping the distribution of gas; e) further increasing the distribution rate of the liquid; and f) decreasing the distribution rate of the liquid. A method of distributing gas and liquid during an upflow filtration mode is also included.

A floating media filter including a filter housing with an influent conduit extending into the filter housing, the influent conduit having at least one outflow aperture positioned below an effluent outlet of the filter housing. A floating media is positioned in the filter housing and forms a media bed when the filter is in a filtration stage, the media bed having a lower surface and an upper surface defining a filtration zone between the lower and upper media bed surfaces during the filtration stage. A diffuser trough is positioned in the filter housing such that (i) the lower surface of the media bed, when the filter is in the filtration stage, is below an upper edge of the diffuser trough, and (ii) the outflow aperture of the influent conduit is positioned sufficiently close to a surface of the diffuser trough such that influent flow, during the filtration stage, is initially directed against and/or along the surface of the diffuser trough, and then redirected in a path into the media bed. Finally, the media filter includes a backwashing mechanism causing (i) lowering of the upper surface of the media bed to a point below the upper edge of the diffuser trough, and (ii) creation of an air space in a substantial portion of the filtration zone.

A system and process for removing from an aqueous stream impurities such as grit, particulates, floating debris, suspended solids, turbidity, bacteria, fecal coliform, oil, grease, color, and the like, and for treating an unacceptable biological oxygen demand, chemical oxygen demand, and/or dissolved oxygen by utilizing a treatment system positioned partially in a channel adapted to a flow of the aqueous stream. The treatment system comprises a containment zone for containing the aqueous stream for treatment by at least one of traveling or stationary screen filtration, aeration, anaerobic and/or aerobic digestion, clarification, media filtration, chemical addition, disinfection, pH adjustment, particulate removal, and/or the like. A partition wall is provided to bypass untreated water such as storm water. After passing untreated waste water through the treatment zone, the treated aqueous stream may be recycled for further use or discharged to its desired destination, such as a lake, river, or ocean.