UNDERSTANDING GROUNDWATER POLLUTION OF SISSILI CATCHMENT AREA IN BURKINA-FASO

In Burkina Faso, groundwater in hard rock aquifers represents a major asset for the rural populations.  But this water is subject to anthropic and natural pollutions as is the case with the sub-watershed of Sissili for which few studies are available. Therefore, it is appropriate to follow their state of pollution. This study aims at a physicochemical characterization of the groundwater quality in order to highlight its relationship to the human and natural environments.  As a result, 67 groundwater boreholes were analyzed according to WHO recommendations (2008) and techniques for assessing the quality of groundwater described by Rodier (2009).  The results show that the chemical quality of water comes from several processes, which leads to a very complex situation. Water is strongly corrosive and is saturated with calcites.  The groundwater is bicarbonated calcic and magnesian. The values of the electric conductivity of water show that the groundwaters are slightly mineralized with a maximum of 639 μ S / cm.  The value of the pH oscillates around 7 which is generally acid.  The chemical hydro analysis revealed the contents in arsenic, fluorine, cyanide, lead, iron, potassium, phosphate, and aluminum exceeding WHO recommendations. The attention must be paid to the minor ions, heavy metals, and metalloids.