About 24 samples from hand-dug wells and boreholes were used to characterize concentrations of the main inorganic ions in a laterite environment under semi-arid climatic conditions in Tikaré, northern Burkina Faso. It was found that the most represented groundwater anion in groundwater was HCO3− with average levels of 49.1 mg/L in the dry season and 33.5 mg/L in the rainy season. The most represented cation was Ca2+ with mean concentrations of 13.7 and 9.5 mg/L, respectively. The main processes, which influence the concentrations of these ions, are evaporation (dry season), local enrichment of recharge water in some elements, ion exchange and fixation by clay minerals (in case of K+). The best correlations were found between Ca2+ and Mg2+ (r = 0.95), Cl− and Na+ (r = 0.95), HCO3− and Mg2+ (r = 0.89), HCO3− and Ca2+ (r = 0.89), and between HCO3− and Na+ (r = 0.80). In general, the quality of the groundwater from the different wells sampled for this study was good enough to serve as drinking water. However, there were situations where the quality of water was polluted because of anthropogenic contaminants (mainly NO3−, K+, Cl−) from septic tanks and manure pits located in the vicinity of some sampled wells. In addition, application of fertilizers also represents a potential anthropogenic contamination source with regard to SO42−, Ca2+, K+, Na+, and Mg2+. Considering the high concentrations of SO42−, Mg2+, Na+ and Ca2+ found in one borehole, the deeper, fractured aquifers were also likely to be enriched in these elements. In contrast, the shallow aquifers are likely to be contaminated with Cl−, NO3− and K+. Cl− and K+ seem to be locally present in recharge water as shown by their relative higher mean concentrations in the rainy season samples.

laterite groundwater Main ion concentration Anthropogenic contamination Correlation Burkina Faso Tikaré