The term non-collective sanitation, or autonomous sanitation, generally refers to all of the treatment stages that allow the purification of wastewater from an individual, single-family dwelling, in principle on the plot of land where the dwelling is located, without transporting the wastewater. An extension (rarer) concerns the treatment of wastewater from several neighbouring houses on a private plot. This is known as grouped non-collective sanitation. On the other hand, a grouping that includes a small collection network and a treatment system (sewage treatment, filter bed, etc.) on communal land is a collective sanitation1 since it is connected to a public network.