Assessment of the Impact of the Saltwater Wedge on the Physical-Chemical Quality of Groundwater in the Grand-Popo District (Southern Benin)

In coastal areas, freshwater aquifers are exposed to saltwater intrusion, threatening their quality. This study, carried out in the Grand-Popo district of Benin, assesses the impact of salt water intrusion on the physico-chemical quality of groundwater. Twenty wells in ten villages were sampled. Analyses revealed high levels of electrical conductivity and concentrations of chloride and sodium ions, often exceeding the standards set by the WHO (World Health Organization). A significant correlation was observed between chloride and sodium ions (R2 = 0.84), confirming the influence of the salt wedge. The results highlight an increased health risk for local populations, justifying reinforced management of water resources.