The karst system of Ghar Boumaza is constituted of a large network of underground galleries explored over 18km. It is drained by several sources among which the most important is A.Taga. These groundwaters are of a good physic-chemical quality used both for drinking water and irrigation. This system is very sensitive to pollution by its karst constitution. A perimeter of protection is essential to preserve these water resources.
The cartography of the intrinsic groundwater vulnerability of this system was realized by applying the R.I.S.K. method (Rock aquifer, Infiltration, Soil and Karst). The resulting map has shown that more than 66% of the surface of the system is in high vulnerability area, about 5% in very high vulnerability, 29% with moderate vulnerability and a small area of 0.02% of the total surface of the system in low vulnerability.
The superposition of the map of intrinsic groundwater vulnerability with the map of polluting sources established for Ghar Boumaza karstic system helped to develop a map of pollution risks in which the areas that are most threatened by the pollution are highlighted including the surrounding area of A.Taga. Water bacteriological analysis campaign of this system was performed recently which allowed discovering that some water sources are contaminated and therefore undrinkable. This allowed us to validate the obtained map. At the end of this study recommendations are made for designing protective perimeters of these groundwater catchments.