Water is the essential element to develop and maintaining life, that’s why the adoption of means of conservation of this essential resource is necessary. In Brazil, the ordinance number 2914, fromDecember12th, 2011, of the Ministry Of Health establishes microbiological parameters, which determinate it’s quality, verifying it’s potability in order not to offer health risks. The research analyzed five samples from two different wells, placed in the same district of Grajaú-MA. The physical-chemical conditions were analyzed by the following parameters: Total alkalinity, Chlorides, Total hardness, pH, Iron, Ammonia, Chlorine, Consumed oxygen, Water turbidity and Color and microbiological, by the multiple tubes methodology based on the most likely number (MLN). Followed by seedlings on selective culture means. The results obtained in this research show that the samples of underground water from five analyzed spots do not match the legislation, because they do not fit to the potabilitystandards. This way, new analysis must be made, mainly microbiological and biochemical tests, to, this time on, adopt means that allow a proper treatment to this water that is used by the local communities.
