Assessment of Heavy Metals in Surface and Groundwater Samples from The Vicinity of Kurudu Solid Waste Dumpsite, FCT, Abuja, Nigeria

Abstract

Given the documented threats posed by heavy metal contamination to environmental and public health, this study assessed heavy metal concentrations in surface and groundwater around the decommissioned Kurudu dumpsite in Abuja, FCT. Groundwater samples were collected from two boreholes (GW1 and GW2) and one hand-dug well (GW3) within the vicinity of the dumpsite. Surface water samples were obtained from Oja River at three points—upstream, midstream, and downstream - between February and March, from 8:00 a.m. to 12:00 p.m., using 500 mL specimen bottles. Data analysis was performed using Analysis of Variance (ANOVA), with mean separation by Duncan’s Multiple Range Test, while metal concentrations were determined using Atomic Absorption Spectrometry. The results showed iron concentrations of 0.40±0.11, 0.09±0.02, and 0.15±0.01 mg/L in GW1, GW2, and GW3 respectively. Lead was not detected in GW1 and GW2 but recorded 0.001 mg/L in GW3. Zinc concentrations were 0.35±0.20, 0.21±0.04, and 0.15±0.01 mg/L, while copper concentrations ranged between 0.04 and 0.05 mg/L across groundwater samples. Magnesium values ranged from 6.00 to 7.50 mg/L, and manganese ranged from 0.09 to 0.62 mg/L. In Oja River, iron concentrations ranged from 0.02 to 0.81 mg/L, while lead levels (2.20–3.22 mg/L) exceeded FMEnv standards for irrigation water. Zinc levels also increased downstream. Overall, cadmium and manganese in groundwater exceeded permissible limits, indicating that the Kurudu dumpsite has negatively impacted groundwater quality and poses environmental and agricultural risks.