Groundwater quality appraisal of some hand-dug wells and boreholes around okemesi and ikoro area, south western Nigeria.

Olusiji Samuel Ayodele

Department of Geology, Ekiti State University, P.M.B. 5363, Ado-Ekiti.

Email: riksam2002@yahoo.com; riksam2002@gmail.com

Accepted 28 September, 2012

Abstract

The study area falls within the basement complex of southwestern Nigeria. The  dominant lihologic units  are quartzites of Effon Psammite Formation which occur mostly as massive quartzites, schistose quartzites and quartzite schists. Fifteen (15) water samples were collected from the study area at regular intervals which includes nine (9) samples from Okemesi Ekiti and six (6) samples from Ikoro Ekiti respectively. These samples were analysed in order to determine their physical, chemical and bacteriological characteristics. The physiochemical results showed that temperature ranges between 26.7ºC-27.7ºC, conductivity (80-1680)µs/cm, appearance is clear, colour in hazen scale is <10 for all samples, turbidity (0-9.35)NTU which showed that the water are less turbid,  tasteless and odourless,  pH (5.96-7.74) which is slightly acidic to  alkaline, total dissolved solids (53.6-1126)mg/l and total hardness (28-414)mg/l. The cations and anions range as follows in the samples; Ca²⁺ (16-254)mg/l, Mg²⁺ (12-226)mg/l, Cl^- (5.99-210)mg/l, NO₃^- (0.98-30.8)mg/l though not detected in all the samples, Fe (0.27-0.67)mg/l, Na⁺(3.89-137)mg/l, Mn(0.008-0.018)mg/l, HCO₃^- (6.0-126)mg/l. All the cations and anions analyzed conform to WHO (1993) standard for drinking water as all their values fell within the maximum permissible limits. The bacteriological analysis for total coliform/100ml as in total bacteria counts range between (7-16) Cfu/100ml, these shows a relatively high load of bacteria in the tested samples.

Keywords: Okemesi; Ikoro; Lithologies; Parameters; Statistics.