Hydrogeochemical characterization and suitability study of dug well water for domestic purpose were carried out
in a semi-arid rural village in Burkina Faso. Thirty water samples were collected from 15 wells in dry and wet
seasons, 2017. Electrical conductivity (EC) and total dissolved solids as well as major ions of all samples were
within the World Health Organization (WHO) permissible limits for drinking water. In contrast, nine wells had
pH beyond the WHO limit during the dry season and one well had very high NO3- concentration in the wet
season. Most wells were seriously polluted with total Cr (CrT) in both seasons (11 and 14 wells in dry and wet
seasons, respectively). Although Pb was not detected in the wells during the dry season, six wells showed Pb
concentrations exceeding the WHO guideline limit for drinking water in the wet season. Graphic interpretation,
including the Piper diagram, major ion ratios and Na/Cl versus EC, were used to characterize the hydrochemistry
and water – rock interaction within the wells. The dominant hydrochemical facies of the wells was Ca-HCO3
during the dry season, reflecting the influence of silicate weathering. Following loadings of agricultural and
domestic effluent, the hydrochemical facies shifted to more mixed type during the wet season. All samples had
negative chloro-alkaline indices, suggesting retention of Ca2+ and Mg2+ by the aquifer materials and release of
Na+ and K+ into the groundwater. In addition to silicate weathering, the hydrochemistry and water quality of the
majority of the wells were partially controlled by the evaporation process and longer water–rock interaction in
the dry season. In contrast, recharge and dilution effects appeared to alter the natural hydrochemistry of the wells
in the wet season. Geochemical characterization has clearly shown that seasonal changes do affect the dug well
water quality. The study also demonstrated that, in terms of CrT and Pb, water from the majority of the wells was
not suitable for drinking. A special attention should be therefore paid to groundwater quality protection in the
area.

domestic water supply, semi-arid, rural Burkina Faso, dug well, hydrochemistry