Filterhuis

Filterhuis, Dutch for “filter house,” is a term used in water treatment to describe a building or module that contains filtration equipment used to remove suspended solids from water or wastewater. It forms part of a treatment plant and may contain one or more filter vessels or modules, along with related piping, underdrains, chemical dosing equipment, and controls.

Filtration occurs as water passes through media such as sand, gravel, and sometimes anthracite or activated carbon. The filter beds are housed in filter vessels arranged in parallel for maintenance and redundancy. An underdrain system collects the filtered water and conveys it to the effluent piping, while sensors monitor the hydraulic headloss across the media.

Backwashing equipment, with pumps, air scour, and rinse water circuits, cleans the media when clogging occurs. The filterhouse may also include a washwater channel, a small chemical dosing area, and a control room with instrumentation. In many plants, multiple filters run in parallel to ensure continuous operation and allow staged maintenance. Modern filterhouses support rapid gravity filtration, membrane filtration, or combinations thereof, depending on water quality requirements.

Historically, filterhouses have been central to drinking water treatment since the 19th century, evolving from simple gravity beds to sophisticated, automated units. Today they are common in municipal waterworks and, in some cases, in industrial or wastewater facilities.