Abstract
This research investigated the extent of heavy metals present in the groundwater due to its contamination by petroleum hydrocarbon. Ten hand-dug wells were sampled within the test area and tested for 23 selected heavy metals. A carefully selected well at the upstream with no history of contamination was selected for the control samples. Concentrations of heavy metals were found to be lower in the Control Well compared to the petroleum hydrocarbon-contaminated wells. The Contaminated wells are dominated by B, Zn, Fe, Mn, and Ni in order of B>Zn>Fe>Mn>Ni respectively. Other metals were found in very low concentrations and largely below maximum acceptable concentrations by World Health Organization and United States Environmental Protection Agency. A comparison between the low concentration of heavy metals observed in the Control Well and the relatively high concentrations in contaminated wells showed strong indications of petroleum-hydrocarbon pollution.