In places with poor water supplying systems, the families store water at home without take care about his contamination. The most efficient action to supply secure water is, unquestionablily, the instalation of public supplying systems, but this objective is distant. So, the domestic systems of water disinfection are the alternative to this places. The system of disinfection of water and food at home are the result of a technology developed with a sistemic view, that mix technical, educational and communal management elements. His objective is to improve the water quality and the health behaviour of the people. It represents an immediate and low-cost alternative; it uses reliable and cheap equipment; it provides health education; it allows the fortification of the communitarian organization due to the population participates from the beginning of the project and assumes the system management. It has some limitations, it´s a long term work and sometimes people don´t want to pay the disinfectant. The criteria to use this technology are: high incidence of EDA´s; lack of secure water; demanded by people; possibility of collect some places to save money; support of local institutions.