Introduction the human being always constructed its residences in places where it had water of easy access, being this used for the maintenance of the life, necessary for the chemical reactions in the organisms, beyond being used for the basic necessities, as to take bath, to cook, to wash clothes, in the industry, the commerce, at last, for the survival and better quality of life. With the evolution of science and technology and the increase of the urban populations, techniques of exploration, water distribution and treatment have been improved with intention to improve the quality of life of the people. In Brazil, with the urban growth and the construction of great metropolises and megalpoles, it had the sprouting of responsible companies for the distribution, treatment and water retraction in the cities, that before, was done for individual workers, and if it only restricted the water delivery in the residences. This transformation of rendering of individual services stops great specialized companies if in accordance with gave the evolution of the demands, that had been if becoming complex more. The initial concerns only related the captation and distribution of the water, with elapsing of the time, had been if extending to the sanitary problems, that had had great growth in virtue of the inadequate disposal of human dejections. We can affirm despite beyond the necessities of investments in collection of sewers also it passed to be demanded of these rendering, investment in development of techniques and application of the same ones in treatment of sewers (OLIVEIRA, 2005). In Brazil public nets exist and private that carry through the distribution work, it has collected and water treatment, the public nets are in being able of the state, however, represented for the municipal and state institutions, average small the private nets can be companies, of national character, who act in the exploration of underground water and distribution and the great companies, who can be national or foreign, the collection and treatment of sewers in the great cities act in. .