Groundwater geochemistry and the genesis and distribution of groundwater fluoride in the Bolgatanga and Bongo Districts, Ghana

Geological, geochemical and groundwater data were used in order to describe the physical flow of groundwater, groundwater geochemistry and the genesis and distribution of groundwater flouride in the Bolgatanga and Bongo Districts of Ghana.;Groundwaters of the study area are low in mineral content. There is a good positive correlation between calcium, magnesium, sodium and bicarbonate ions and electrical conductivity. The source of the major ions in the groundwaters is probably dissolution of feldspars and ferromagnesian minerals. Groundwater types in the study area are CaMgHCO;Concentrations of groundwater fluoride in the study area range from 0.11 to 4.60 ppm, with the highest concentrations found in the fluorine enriched Bongo Granites. The depth variability of groundwater fluoride in the Bongo Granite indicates that the mean fluoride concentration decreases with depth. Eighty-five wells have fluoride concentrations above the World Health Organization (WHO) recommended maximum guideline value of 1.5 ppm and may cause dental fluorosis in children drinking the water. Nitrate levels ranged from 0.02 to 211.00 ppm with 19 water samples exceeding the WHO recommended limit of 45 ppm. The sources of nitrate pollution are suspected to be anthropogenic with the highest concentrations found in the towns and sizable villages.