Determination of the Concentrations of Heavy Metals in Borehole Water near Refuse Dump Sites around the University of Cross River State (UNICROSS) Calabar, Nigeria

The contamination of groundwater from the infiltration of leachates into aquifers and health risks on residents drinking from boreholes around dumpsites informed this study on the levels of heavy metals in the boreholes around the University of Cross River State (UNICROSS) dumpsite. Borehole water samples were aseptically collected from 3 boreholes at 50, 80, and 200 meters respectively from the dumpsite into a one-liter sampling bottle and preserved in an ice chest. The samples were then analyzed for heavy metals using Atomic Absorption Spectrophotometer. The values obtained were compared with WHO permissible standards for drinking water. The mean concentrations of Pb (0.614 ± 0.008), Cd (0.399 ± 0.053), As (0.023 ± 0.002), and Co (0.002 ± 0.001 mg/l) in the borehole water were significantly higher than WHO permissible limits, while the concentrations of Cr (0.002 ± 0.001) and Ni (0.056 ± 0.004) were significantly lower than the WHO permissible limits. The increasing trend of heavy metals in the borehole water was Cr = Co < As < Ni < Cd