Investigations carried out at Chile have determined that certain soils placed over the years as a product of the volcanic activity can be suitable for use as filter material in domestic wastewater purification. These soils have been studied by Universidad de Chile researchers, who have defined the main characteristics of the most important Chilean volcanic soils and, according to the properties studied (such as porosity, surface area and density, among others) have alleged that these materials exhibit water filter behaviour. As results of this research, first of all, the existing geotechnical information on Chilean volcanic soils has been complemented, such as hydraulic conductivity and, has been evaluating the influence design parameters, such as thickness of volcanic soil layers and the application rate of wastewater, in the purification of domestic wastewater.