Horizontal helophyte filter

Erasmusgracht Amsterdam: horizontal helophyte filter for purifying wastewater and rainwater © atelier GROENBLAUW, Madeleine d'Ersu

Besides the system described above, filters also exist through which the wastewater passes horizontally. These filters do not require drainpipes or pumps and are therefore simpler in their construction. As such, this type of filter requires less maintenance than vertical filters. Its uses include treating polluted runoff from roads and car parks.

Schematic of a horizontal helophyte filter, rainwater from the road settles, helophyte filter purifies and clean water flows to surface water. - Source: atelier GROENBLAUW