There is currently no single, explicit, globally recognised definition of greywater. European Standard 12056-1 defines greywater as wastewater with a low pollution level and no faecal matter such as produced by shower, bath, wash basin and washing machine and that can be used to prepare service water. In contrast, wastewater from the kitchen is not included due to the high levels of fats and food waste it contains. 

The use of greywater, like the use of rainwater or well water, is a suitable way of reducing potable water consumed in buildings, helps protect the environment and lower the costs of water consumption. Furthermore, less wastewater is produced as a result of recycling greywater since the water is used twice, which leads to additional ecological and economic potential. It can be safely said that greywater recycling in large groups of buildings and hotels can be a sensible means of saving water and wastewater with little effort and offers significant returns due to its relatively low level of contamination, representing an extremely efficient way of cutting costs.

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Treating greywater

There are various technical approaches to recycle greywater. Technologies differ considerably in their complexity, size, recycling performance and recycling quality. There are direct-use systems, retention systems as well as physical, chemical, biological and bio-mechanical systems. 

Comparative studies have shown that the membrane bio-reactor (MBR) currently represents the best technology to recycle greywater due to its outstanding cleaning performance. Greywater systems using MBR technology also have the advantage that they require little space and can guarantee the relevant quality parameters even if the inflow characteristics fluctuate, which means that the requirements of the European Directive concerning the quality of bathing water are always guaranteed.

Functionality of the greywater recycling system

ewuaqua greywater systems work with state of the art technology using MBR equipment. Our greywater systems are designed to treat and clean greywater from showers, baths and wash basins. Wastewater from kitchens should only be connected with an additional pre-cleaning system due to the fats contained in the wastewater. The barrier effects of the immersed cartridges with ultra-filtration membrane (with a pore size of 0.00005 mm) used in our technology mean that we can guarantee the safe and complete retention of all dirt particles and the complete retention of all bacteria; even the smallest viruses are removed with a retention rate of 99.999 %. This allows for the recycled water to be used at all points of consumption where potable water is not required. We recommend using the water for flushing toilets, cleaning purposes, washing the car and watering the garden.


Elektrische Tauchpumpen aus hochwertigem Edelstahl für Entwässerung und starkes Schmutzwasser mit schwimmenden Festkörpern. Die Pumpe ist mit einem Schneidwerk ausgestattet, welches Festkörper vor dem Abpumpen zerkleinert. Der Motor ist ölgekühlt und mit einer doppelten Gleitringdichtung ausgestattet. Die hohe Förderleistung wird durch die hochwertigen Motoren mit 1 oder 3 Phasen und einem integrierten Überlastschutz gewährleistet. Die Pumpe ist mit 10 m Kabel H07RN-F ohne Stecker ausgestattet und kann somit vom Nutzer individuell angeschlossen werden. Version A ist mit einem Schwimmerschalter ausgestattet.