V3I3P24

Groundwater Quality and Heavy Metal Contamination in Borehole Water from Pb-Zn Mining and Quarrying Areas of Ebonyi State, Nigeria: Implications for Human Consumption

Osayande, A.D^1*

Abstract

Clean and pure drinking water availability is a basic human right, but the activities of mining have been found to adversely affect the purity of water in many resource-endowed developing countries. The present study aims to evaluate the physicochemical parameters and heavy metal content of borehole water samples collected from different Local Government Areas of Ebonyi State, Nigeria. The borehole water samples were collected at a depth of 120–180 m. The sampling sites included Ikwo, Abakaliki, Ezza South, and Ivo Local Government Areas of Ebonyi State, Nigeria. Samples were analyzed for pH, temperature, turbidity, TDS, TSS, COD, conductivity, nitrate, phosphate, sulphate, Ni, Zn, Cd, As, and Pb using AAS and titrimetric methods. Results indicate that pH (6.89–7.16), turbidity (1.24–2.35 NTU), TDS (109–126 mg/L), and conductivity (193–216 µS/cm) are within WHO permissible limits. However, Pb concentrations (0.047–0.210 mg/L) exceeded WHO limits (0.01 mg/L) in 75% of samples. Cd exceeded limits in 50% of samples. Arsenic exceeded limits in 50% of samples. Ni and Zn were within limits. The contamination is attributed to leachate infiltration from abandoned mine tailings and fugitive dust deposition. Urgent water treatment interventions are required to prevent chronic heavy metal poisoning in resident populations.

Keywords:

Groundwater contamination; Borehole water; Heavy metals; Pb-Zn mines; Drinking water quality; WHO standards