In the northwestern part of the Zinder region, the study area, the Continental Hamadien aquifer, captured by numerous modern structures, represents the main source of drinking water supply for the populations of the area. It is a highly populated area where the problem of water resources is acute. Furthermore, the water coverage rate is one of the lowest in the country, 57.46% against 70.85% the national average. In this area, water quality is aggravated by the levels of certain chemical parameters, including fluorides, hence the present study, the main objective of which is to determine the percentages of fodder with high fluoride levels in order to know their impact on the rate of drinking water supply to the populations of the area. At the end of the chemical analyzes of groundwater samples, the outcome of the analyzes made it possible to establish that 23% of modern sample water points present fluoride levels exceeding the limit set by the WHO for drinking water of drink (1.5mg/l), therefore, these waters are unfit for human consumption. Data analysis showed that this fluorinated pollution concerns three (3) areas, the first is between the villages of Karagoua Makéra, Tirmini and Toudou Agoua while the second covers the axis of the villages of Garagoumsa, Koundoumawa and Djetaou with a single water point in Takièta and finally the third, is located northeast of the city of Zinder on the axis of Birni Kazoé. Moreover, the origin of these fluorides in the groundwater of the area would result from the increase in the fluorine content (CaF2), of the detrital reservoir, formed exclusively of products resulting from the alteration of the crystalline massifs forming the shield. nigerian.