DIAGNOSES OF THE POTENTIAL SOURCES OF THE ANTHROPIC POLLUTION OF THE NIGER STREAM AROUND THE CITY OF NIAMEY (NIGER)

During its crossing in the agglomeration of Niamey, the Niger stream serves as spillway of the garbage as a dump for both solids and liquids generated by the industrial and domestic activities. The main objective of this study is to identify all garbage resulting from the activities of the population of Niamey bordering to the Niger stream. Some interviews have been led by the taking parts responsible for the production and the management of the urban garbage, followed by the investigations of the land through the observations of the states of the banks of the stream and the urban infrastructures of purification of the garbage. The gotten results reveal that on twenty-one (21) establishments investigated only six (6) pre-treatmentfacilities for their effluents. Also, the network of purification of used waters of the city of Niamey is the unit type, and deprives functional works of purification of the urban worn-out waters. The city of Niamey rejects sewages of used waters in the Niger stream through thirty-seven (37) points of the dismissals identified along the banks of the Niger stream, of which thirty-four (34) on the left strand and three (3) on the right strand, therefore the less exposed to the pollution. On the other hand, the abduction of the solid garbage endures an insufficiency, of such sorts that garbage is evacuated in the gutters, the valley of Gounti-yéna to be drained at the stream or poured directly on the banks of the Niger stream. Thus, thirty (30) points of stripping of the garbage near the course of the Niger stream have been identified of which seven (7) garbage dumps out of the right strand and twenty-three (23) on the left strand. Indeed, the anthropicsources of the pollution of water of the Niger stream in the city of Niamey result from dismissals of garbage and the worn-out water essentially bound to the activities of the city.