Groundwater is formed by infiltration water and is free of pollution. However, it can be contaminated by the drawing technique, the proximity of latrines or other sources of pollution, the lack of protection. It can be loaded by the elements; brackish water (NaCl), hard water (Ca2 +) or Ferruginous (fe2+). The main purpose of our study is the monitoring of quality parameters during the physicochemical treatment for the removal of iron and manganese from the groundwater of the Gharb aquifer by the Mechraa Belksiri station. The results of the analyses carried out on the groundwater of the city of Mechraa BelKsiri show that they present exceedances compared to the limits set by the Moroccan standard. We highlight these exceptions for iron which exceeds 0,4 mg/l and manganese which exceeds the standard 0,1 mg/l up to 0,5 mg/l. Even if the presence of iron and manganese in drinking water does not constitute a public health problem, the WHO prescribes, as a guideline value, an iron concentration equal to 0,3 mg/l, and 0,1 mg/l for manganese. These waters require treatments in order to make them of good quality and suitable for human consumption in order to avoid potential problems related to their presence. There are currently two conventional processes to eliminate them: biological processes and physicochemical processes.