Assessment of Water and Stream Sediment Pollution Related to Artisanal Mining in Alga, Burkina Faso, West Africa

Burkina Faso, like several other countries in the Sahelo-Sahelian strip, has seen a significant change in its mining sector in recent years through the development of the industrial and artisanal mining sub-sectors. The purpose of this study is to assess the level of pollution of water and stream sediments in the study area. A total of twenty-eight samples were taken, including three surface water samples, nine groundwater samples, ten stream sediment samples and six mine tailings samples. The analysis of the physico-chemical parameters and the metal content (cadmium, chrome, copper, mercury, nickel, lead, zinc and arsenic) of the water show that the values meet the drinking water standards in force in Burkina Faso. However, the various indices calculated, namely the geo-accumulation index (Igeo), the contamination factor (CF) and the enrichment factor (EF) show that the total metal contents of stream sediments are not d lithogenic (natural) origin but attributable to artisanal mining in the village of Alga. They highlight metal pollution with high levels of arsenic and cadmium and extremely high levels of mercury.