Sanitation has been around since the dawn of civilisation, but little progress has been made over the years. Half of the Brazilian population has no sewage collection and around 35 million people have no access to treated water. The aim of the study is to propose a more economical wastewater treatment alternative, mainly for rural areas using biofertiliser, but this methodology can also be used in urban areas that do not have a collection and treatment system. The methodology consists of installing 3 tanks of 1000 litres each, connected to each other. The first box is connected to the toilet where the domestic effluent is degraded, removing up to 70 per cent of the organic matter, the rest in the second box, and the third is free of contamination. The resulting effluent can be used as biofertiliser or through other disposal methods. The method is gaining more and more ground due to certain factors: lack of specialised labour, low-cost installation, no odours, increased income generation for the community, as well as the health and environmental benefits of not contaminating soil and water.