GEOELECTRIC AND PHYSIOCHEMICAL METHODS TO CHARACTERIZE SUBSURFACE CONTAMINATION IN PART OF KOLOKUMA/OPOKUMA ENVIRONS, NIGER DELTA, NIGERIA

Abstract

Three (3) Vertical Electrical Soundings (VES) were carried out using Schlumberger array to obtain geophysical data in the study location, acquired with the ABEM SAS 1000 terrameter earth meter, to characterize contamination in relation to the depth and thickness of viable aquifer of the subsurface lithology. Two (2) water samples were collected from the study area, analyzed to determine the concentration of contaminant, using the Atomic Absorption Spectroscope (AAS). Result revealed high contaminant contents of Cobalt (Co) as 0.3015 mg/kg in sample A and 0.2439 mg/kg in sample B, exceeded the World Health Organization (WHO) permissible limit, which indicates that aquifer is likely below 2 m down the subsurface, may likely be polluted and geoelectric layers of topsoil, sand and clay traces. It is advisable to carry out proper water treatment from source; for potable drinking water, and the result clearly show that the geophysical and physiochemical method was very effective for the interpretation of the contamination in subsurface.