Geoelectrical investigation of groundwater potential, at Nigerian Union of Teachers Housing Estate, Paggo, Minna, Nigeria.

Abstract

Vertical electrical sounding (VES) was carried out to evaluate the groundwater potentials of Nigerian Union of Teachers Housing estate, Paggo, Minna. The ABEM Terrameter model SAS 4000 was used to collect the subsurface data for the evaluation of groundwater potentials. Six profles with ten VES stations on each profle were sounded with intervals of 100 m apart. It has a maximum current electrode separation (AB/2) of 100 m. Three and four geoelectric layers were obtained which include: topsoil, weathered layer, fractured layer and fresh basement layer. The stratigraphy of the subsurface shows: topsoil (67.5–835.1 Ωm), weathered layer (108.0–939.7 Ωm), fractured layer (118.9–242.0 Ωm) and the fresh basement layer (1041.0–9704.0 Ωm). Sixteen VES points were recommended as groundwater potentials of the area having weathered/fractured layer resistivity varying between 65.84 and 454 Ωm, depths range from 10.61 to 26.37 m, and thickness varies between 9.255 and 24.69 m. The observed frequencies in curve types include 58.33% of H, 26.67% of A, 10% of HA and 5% of AA. A correlation of the borehole log data with the VES was made and is in agreement. Viable boreholes for good portable water should be sited at VES stations A10 and D9 with a reasonable thickness of 21.2 and 10.68 m, respectively