Impact of anthropogenic and environmental conditions on surface run-off quality: a case study of Nsukka, Eastern Nigeria

This is aimed at assessing the effect of the analysed physico-chemical, microbial parameters and heavy metals on run-off in selected routes at Nsukka Urban. The major roads selected included campus gate (CG), Ikenga road (IR), Enugu road (ER) and Ikpa/Orba road (IKPR); with university market road serving as control location (C). Four run-off samples were collected from each of the selected roads; in October 2020. The heavy metals were analysed using the Atomic Absorption Spectrophotometer (AAS); other parameters were analysed using standard methods. The results revealed that the analysed metals concentrations ranges from (in ppm): Cd (0.00-0.09), As (0.23-1.58 mg/L), Fe (6.48-79.72), Hg (.00-3.00), Pb (0.25-0.75), Ni (0.21-0.92), Mn (0.10-0.21), and Cr (0.67- 01.33) indicating increase in the concentration of samples as against control showing anthropogenic influences. The results also unravelled that metal concentrations are above the permissible standards for potable water. Coliform ranged (0.00-1736.00 cfu/mL), Turbidity (22.50-52.80 NTU) and Organic matter (55-130 mg/l). All other parameters like pH, EC, K+, Mg2+, and Na+ are all within the permissible limit of WHO. Multivariate and Sorensen analyses were also employed to separate chemical variables into components which gave a clue to the different sources of contaminants within an area, based on the indicator parameter associations. This analysis unravels anthropogenic contamination from domestic solid and sewage wastes on the quality of surface run-off and should be mitigated.

Automated summary

This study aimed to evaluate the impact of physico-chemical, microbial parameters, and heavy metals on runoff in specific routes in Nsukka Urban. Four major roads were selected, including campus gate (CG), Ikenga road (IR), Enugu road (ER), and Ikpa/Orba road (IKPR), with university market road serving as a control location (C). The results showed that the concentrations of heavy metals exceeded the permissible standards for potable water, indicating anthropogenic influences. Additionally, the presence of coliform, turbidity, and organic matter further highlighted the contamination of surface runoff from domestic solid and sewage wastes.