In the rural zones with low population densities which are characteristic of the Atlantic Area, the absence of a system for treating water residues leads to the dumping of effluents in nearby natural areas, leading to diffuse pollution in these zones which are of great ecological value. In this context, DEPURANAT proposes to put together a system for the sustainable management of waste water, encouraging reutilisation of this in natural areas. The main objective of the project consists of stocking the water recovered locally, treating it in situ with small decentralized systems, and re-using the sub-products obtained. Cheap and simple to install, these decentralized systems contribute to improving the treatment of water and will encourage sustainable economic and financial development for rural areas.