Phytodepuration, as a wastewater treatment process for small agglomerations with low pollutant loads, has proved its worth in many countries around the world. In Algeria, few attempts have been made at the investment level, preferring to mature research on experimental pilots. To this end, two case studies have been carried out by our laboratory: a scale model set up at the University of Mascara's experimental farm, and a full-scale pilot plant at Brezina (El Bayadh). The TMEs are stored in a finishing tank before being recycled for crop irrigation. With its significant and encouraging results, the phytodepuration process offers a highly justifiable opportunity to contribute to the challenge of saving water and managing it efficiently, particularly in small communities. The aim of this book is to shed some light on this ecological purification process, followed by an example of a sizing calculation.