Dr. Kathe Seidel at the Max Planck Institute in Plon, Germany, tested the ability of bulrushes to treat wastewater. Her discoveries led to the first subsurface CW for municipal wastewater treatment in 1974 in the community of Liebenburg-Othfresen, Germany.
<ref name = "Verhoeven">Verhoeven, J. T. A., Beltman, B., Bobbink, R., & Whigham, D. F. (2006). Wetlands and natural resource management. New York: Springer.</ref>
The first free water surface CW was implemented in The Netherlands in 1967. This system had a star-shaped layout and was called a "planted sewage farm". <ref name = "Verhoeven"/> During the later 20th century, the popularity of CWs grew in Europe and North America. CWs have traditionally been used to treat sewage but, since the late 1980s, have been used to treat a variety of wastewater types such as
domestic wastewater, mining and industrial wastewaters, agricultural wastewaters, landfill leachate, stormwater, and runoff. <ref name = "Verhoeven"/> <ref name = "Kivaisi"/> In developing communities, they can be used to treat greywater or used as a secondary treatment for domestic sewage.