Hydro-geochemical evaluation of groundwater quality in Akoko North West local government area of Ondo State, Nigeria

  • Temitope Dare Timothy Oyedotun Department of Geography and Planning Sciences, Adekunle Ajasin University, Akungba-Akoko, Ondo State, Nigeria.
  • Opeyemi Obatoyinbo Department of Geology, Faculty of Science, Adekunle Ajasin University, Akungba-Akoko, Ondo State
Keywords: water samples, physico-chemical properties, water quality

Abstract

A sudden geometric increase in population of Akoko North West Local Government Area of Ondo State has led to an increase in demand for water and harnessing of subsurface water reserve. A total of twenty six water samples obtained from both boreholes and hand-dug wells were analyzed for their physico-chemical characteristics with the aim of assessing their quality, usability and also to determine the level of their contamination in the local government which is dominated by granite gneisses, charnockites, and augen gneisses as the main rock types. The following physico-chemical properties were analyzed for in the samples collected: electrical conductivity (EC), pH, total alkalinity (TA), total dissolved solids (TDS), total suspended solids (TSS), acid neutralizing capacity (ANC) with major cations (Na+, Mg2+, Ca2+), anions (PO43-, HCO3-, SO43-) and several heavy metals (Zn2+, Fe2+, As+, Ni+, Pb2+, Cd+, Cu2+). The following results were obtained from the analysis: Zn2+ (0.109 – 0.437 ppm), Fe2+ (0.216 – 0.726 ppm), As+ (0.01 – 0.03 ppm), Ni+ (0.036 – 0.074), Pb2+ (0.003 – 0.010), Cd+ (0.002 – 0.007), Cu2+ (0.086 – 0.241) with appreciable abundances of PO43-, Cd+, Fe2+and Ni+ some exceeding while some others are below the WHO acceptable level for drinking water, thereby making it a serious source of concern as it indicates varying levels of faecal contamination (from leaky septic tanks, interception with pit latrines) and heavy metal liberation into the water consumed by the residents. It was also noticed that the water was fresh based on the analysis of the Total Dissolved Solids and the Pb2+ concentrations almost exceeded the standard permissible limit. Generally, it was concluded that the overall quality of the ground water is averagely good physico-chemically.

Author Biographies

Temitope Dare Timothy Oyedotun, Department of Geography and Planning Sciences, Adekunle Ajasin University, Akungba-Akoko, Ondo State, Nigeria.
Lecturer, Department of Geography and Planning Sciences.
Opeyemi Obatoyinbo, Department of Geology, Faculty of Science, Adekunle Ajasin University, Akungba-Akoko, Ondo State
Graduate student, Department of Geology
Published
27/04/2012
Section
Papers