FACTORS AFFECTING GROUNDWATER CHEMISTRY

ABSTRACT

Hydrochemical characteristics and quality assessment of groundwater (drinking water) investigations were carried out in Iyuku, Auchi area of Edo state to determine the potential factors affecting groundwater chemistry. Water samples (10) were taken and analyzed for various physicochemical parameters such as total dissolved solids (TDS), calcium (Ca2+), sodium (Na2+), chlorides (Cl- ), bicarbonates (HCO3 - ), carbonates (CO3 - ) and sulphates (SO4 2- ). Results of the analyzed samples indicated that the hydrochemical characteristics and quality assessment parameters were lower than the drinking water standards set by the World Health Organization (WHO), except for TDS which was within the set standard. The evaluation of factors affecting groundwater chemistry was accomplished by interpreting Gibbs plot and Hill-Piper diagram. According to the Gibbs plot, the most dominant factor influencing groundwater chemistry is waterrock interaction and to some extent precipitation exacerbated by mineral dissolution. The HillPiper diagram reveals that the dominant water type in the area is CaCl2 type while the dominant ions are Ca2+ and Cl- . This study shows that natural and anthropogenic sources (agricultural, industrial and domestic activities) influences groundwater chemistry in the study area.