Hydrochemical analysis of water samples from Yenagoa in the Niger Delta shows widespread occurrence of iron (Fe) in the groundwater. The Fe concentration is more than 0.3 mg/L at many places, and the distribution is heterogeneous both vertically and horizontally. In order to identify the cause of the high heterogeneity, we carried out an integrated study consisting of hydrogeochemical, electrical resistivity sounding and induced polarization (IP) chargeability measurements at eleven sites and 2-D electrical resistivity profiling (at 2 sites). Data processing using inversion techniques resulted in 4-layered resistivity and chargeability-depth models. The results show that clean sand and gravel exhibit high resistivity but low chargeability and normalized chargeability values, whereas clay and sandy clay exhibit relatively low resistivity but high chargeability and normalized chargeability values. In sites where the aquifer is overlain by a thick clay layer, Fe concentration is high (Fe > 0.3 mg/L) in the groundwater and redox potential values range between 118 and 133 mV. We interpret that the low-permeability clay layer creates a relatively atmosphere-isolated state in the underlying aquifer, which is responsible for the reductive ambient subsurface groundwater environment. In sites where the aquifer is capped by silt, Fe concentration is low (< 0.3 mg/L) in the groundwater and redox potential values range between 115 and 164 mv indicating a mild oxidation environment. We interpret that the clay acts as a controlling factor to the Fe enrichment in the groundwater regime. Knowledge of the clay layer, which is identified in the present study, will be helpful in selecting suitable sites for boreholes.
Hydrogeological work was carried out to providing an alternative source of portable water supply to Omoku and its environs as their major source of water which is surface water had been contaminated/polluted by oil and gas exploration, exploitation and other anthropogenic activities in the area. To obtaining reliable data and achieving the aim, geoelectric sounding method and Schlumberger array was employed with the use of a digital averaging instrument ABEM terrameter SAS 300 model that displays the resistance measurements directly with a maximum current electrode separation (AB) of 100m. WinResist software computer iterative procedure was used, which aided to obtaining interpreted depths and resistivities from field data. The results of the geoelectric survey were tied to various lithologies by calibrating the geoelectric values with borehole data which enabled us to establish the aquiferous zones. The aquifers were located at depth of about 22m to 30m based soil profile and high resistivity values ranging from 3415m to 4555m. The information from the findings can be successfully used to harnessing and supply safe, portable and sustainable water to the people of Omoku and its environs in Rivers State, Nigeria.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.