Water samples were collected before treatment (directly from the artesian well) the Chadian Water Company (STE): [GD7, GD8. GD16].
The some Heavy metals and Dissolved ions of these samples were determined in the laboratory of the Ministry of Rural and Urban Waters, according to the approved standard methods. The results of the analyzes for various properties were compared with the permissible values and limits of the WHO, EU, and some health and environmental bodies and institutions .the reading  of the samples before treatment for the  studied elements are the more than in the samples after treatment. The Water samples before and after treatment for the sites gave a very large variation in the confidence level of residual chlorine ion (8.89.10^-6 ***) Wihle Ishowed ) NO₃^-,NO₂^-,Cd⁺²,Cu⁺²(respectively (0.00374**, 0.00138**,0.00725**,0.00434** (the two sites (GD8 and GD16) recorded heights average chlorine (0.95 mg/l) it exceeds the permissible limit of WHO. As for nitrate the average of the samples before treatment for )41.67mg/l) it exceeds the limit of the USEPA for nitrate in drinking water (10 mg/l). the Water samples before and after treatment for the three sites of Cadmium ratios  it was all within permissible limits. The heights mean of Copper was recorded in the drinking water samples before treatment in the two sites (GD7 and GD8)  (2.12 mg / l) it exceeds the permissible limits of the SEPA (0.01 – 1.00 mg / l).