GEOELECTRICAL INVESTIGATION OF GROUNDWATER QUALITY THROUGH ESTIMATES OF TOTAL DISSOLVED SOLIDS AND ELECTRICAL CONDUCTIVITY IN PARTS OF AKWA IBOM STATE, SOUTHERN NIGERIA
Journal: Malaysian Journal of Geosciences (MJG)
Author: Akpan Emmanuel F., Akpan Veronica M., Inyang Udeme U.
This is an open access article distributed under the Creative Commons Attribution License CC BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
This paper presents the results of a geophysical investigation of groundwater quality in parts of Akwa Ibom State, Southern Nigeria. A total of 11 vertical electrical soundings (VES) was carried out in the study area using the Schlumberger electrode configuration. The results of the interpretation show that the area comprises 4 geoelectric layers. The third layer constitutes the major economic hydrogeological unit in the area and has resistivity of between 50.3 Ωm and 2088.9 Ωm and thickness of between 36.8 m and 149.0m respectively. The groundwater quality was assessed through estimates of the electrical conductivity and total dissolved solids in water. The conductivity ranges from 74.5 to 604.4µS/cm with an average value of 244.0µS/cm while the TDS values range from 47.7 to 386.8 ppm with an average value of 156.1 ppm. Based on these values, which are within the permissible limits, the water is considered to be fresh and suitable for drinking and other domestic/agricultural usages. The results show excellent correlation between the estimated TDS and the Dar-zarrouk parameters (longitudinal conductance and transverse resistance) on one hand and the aquifer bulk resistivity on the hand which demonstrate the ease of deriving TDS from surface resistivity data.