This information, published on the website of the Madrid Foundation for Knowledge of the Madrid Network for Advanced Treatment of Wastewater with Non-Biodegradable Pollutants (REMTAVARES), relates to a Wastewater Treatment Plant (EDAR) in an area between the municipalities of Galapagar and Torrelodones (Madrid), an area that is part of the Natura 2000 network. For this reason, it became necessary to use efficient, high-performance treatment technology with low environmental impact. The article points out how a biofiltration process using a filter element sold under the name Filtralite® Clean was incorporated into its secondary treatment. The properties of this system and the effects of its implementation in this sewage treatment plant are explained, the waste water of which meets the requirements for discharge into a protected environmental space. On the other hand, it offers a number of advantages of this biofiltration system that can replace other biological treatments.