Water quality assessment of Otun and Ayetoro Area, Ekiti State, Southwestern Nigeria

Abstract

The study areas (Otun and Ayetoro) are situated in Moba Local Government Area of Ekiti State, and lies within latitudes 8°75' N and 9°15' N and longitudes 5°60' E and 6°00' E respectively. The study area also falls within the basement complex of south western Nigeria. The dominant lithologies include migmatites, granite gneisses, quartzites, charnockites and granites. Physical, chemical and bacteriological evaluation of hand-dug wells in the study areas were carried out to ascertain its suitability for human consumption and domestic usage. Water samples were collected at random from different localities in the study areas. Ten hand dug wells water were sampled for their physical, chemical and bacteriological properties and were compared with WHO (1993) standards. The physical parameters showed that pH ranges from 5.2 to 7.1 which is slightly acidic to alkaline, temperature is 25°C and it is uniform throughout the samples, while colour is 5Hu. The chemical parameters revealed that turbidity value ranges from 3.7 to 7.3 NTU, dissolved solids (5.0 to 7.6 mg/L), total dissolved solids (5.0 to 7.6 mg/L), total alkalinity (30 to 180 mg/L), Ca²⁺ (28 to 72 mg/L), Cl^- (50 to 120 mg/L), silica (10 to 14 mg/L), Fe²⁺ (0.01 to 0.05 mg/L), Mn²⁺ (0.01 mg/L), total hardness (120 to 200 mg/L), NO^3- (15 to 75 mg/L) and Escherichia coli (2 to 35 mg/L) which is very high and above WHO (1993) recommended standard value. However, the pH values of some of the water samples conform to World Health Organization standard except sample labelled L 10, which could be as a result of the presence of some contaminants like sulphur or ammonia compounds that might have furnished hydrogen ion into the water. However, the shallow wells met the requirements for human and domestic consumption with minimum scientific treatment.

Keywords: Moba, Otun, hand-dug wells, lithologic units, WHO, contaminants.