Mining Activities: Impacts on the Ikpeshi Village Water Quality

Aims: To study the impact of mining activities on the water quality of Ikpeshi, Edo State, Nigeria.

Study Design: The experimental design of this work involved the collection of water samples from three different sites, transportation and storage of samples, characterization of samples for specific contaminants, and interpretation of results.

Place and Duration of Study: The sample collection sites included a mine pit at a mining site, while a flowing stream and a borehole, both about 1 km from the mine all in Ikpeshi, Edo State, Nigeria.

Methodology: 1500 mL each of water from three different sample spaces (mine pit, flowing stream, and borehole) were collected, stored in a refrigerator, and then analyzed for their physicochemical properties including the pH, electrical conductivity (EC), turbidity, dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), dissolved iron (Fe), manganese (Mn), chromium (Cr), cadmium (Cd), and lead (Pb). The results were then compared against the World Health Organization (WHO) permitted standards for drinking water.

Results: The water samples analyzed showed the concentration of dissolved Cr, Cd, and Pb in mine pit water to be 0.085, 0.093, and 0.09 mg/L respectively. The concentration of chromium (Cr) in the mine pit water was 1.7 times higher than the WHO limit (0.05 mg/L), that of cadmium (Cd) was 31 times more than the WHO permissible limit (0.003 mg/L), while that of lead (Pb) was approximately 12.9 times the WHO cadmium limit (0.01 mg/L). The corresponding values of the flowing streams (0.011, 0.002, and 0.007 mg/L for Cr, Cd, and Pb respectively), however, fell within these WHO limits. Similarly, dissolved Fe and Mn were 0.95 and 0.167 mg/L respectively in mine pit water, 0.37 and 0.061 mg/L in the flowing stream, and 0.24 and 0.018 mg/L in borehole water while the WHO limits for these are 0.3 and 0.05 mg/L respectively.

Conclusion: These results showed therefore that water from the mine pits and flowing streams in these areas are unsafe for domestic consumption and would require a high level of purification before release to the environment or water bodies because their contaminant levels are higher than the permissible limit.