Not only for isolated buildings, but also in scattered locations, the construction of plant-based wastewater treatment systems for the sewage of one or more houses is a financially attractive alternative to the expensive connection to a sewer network. Certain tasks can only be performed by professionals, but self-contribution can significantly help save costs. More and more municipalities are also establishing such systems for ten or more houses instead of a much more complex sewer. Furthermore, the ecological value should not be underestimated. A plant-based treatment system represents an interesting wetland habitat, and since it is almost completely overgrown in its finished state and the main processing of wastewater occurs in the root area through bacteria, there is neither an odor nuisance nor a health risk, for example, for playing children.