Grey water or household water, is water applicable for agricultural, industrial or secondary household use, that does not meet the drinking water standards. The municipality of Raalte (together with water authority “Groot Salland” and drinking water company “Vitens” -the Netherlands), ordered an inquiry into the fact whether the effluent of the municipal waste water treatment plant, could be made suitable for the use as grey water.

For this purpose, Wetlantec engineered a constructed wetland filter in 2000, including a soil filter, that processes the effluent of the WWTP. This construction has been in operation for over a decade now and produces water that meets the desired standards.