Geospatial Analysis of Heavy Metal Intrusion in Groundwater Resources of Isoko North Local Government Area, Delta State, Nigeria

Michael N. Oyem — 2025-03-09

This study compared the regional variations of heavy metal intrusion in subterranean water resources of Isoko North Local Government Area, Delta State, using ten (10) spatially distributed boreholes. The data were subjected to the Heavy Metal Index (HMI) technique to determine the significant contamination rate (with the World Health Organization Standard and the Nigerian Standard for Drinking Water Quality as the control variables). The investigation revealed that lead (Ppm) values ranged from 0.11 to 0.18, with higher concentrations in Owhelogho (0.18), Iyede (0.18), and Ellu (0.17). The Iron (Ppm) value ranges from 0.31 to 0.43, with all locations having significant values slightly higher than the WHO and NSDWQ norm of 0.3. The heavy metal index test yielded a class "II" grade, suggesting the presence of lead and iron oxide in trace amounts. The groundwater potentials and vulnerability assessment level results were validated using the AHP Pairwise analysis program. Rainfall, height, slope, drainage density, lineament density, land use land cover (LULC), and geology are among the components evaluated. It is significant to highlight that rainfall, accounting for 25.88%, and geology, accounting for 23.79%, are the two primary influencing elements in heavy metal contamination of groundwater in the area. The area's vulnerability model, created using a GIS-based weighted overlay, shows 75.5% of the area to be highly vulnerable, 17.22% moderately vulnerable, and 7.29% lowly vulnerable.

Environmental Impact and Physico-Chemical Analysis of Flood Water Intrusion in Domestic Boreholes and Well Water Quality in Isoko North Local Government Area and Environs in Delta State, Nigeria

Jacob Meye — 2025-03-15

Environmental impact and water quality characteristics of flood water intrusion in domestic boreholes and well water quality were investigated with the view to determining the extent of pollution. Parameters such as physic-chemical, heavy metal and micro-biological content were tested for and their impact identified. This research was based on the hydro-geo-pollution cycle as these chemical elements return back to man eventually through the process of bio-accumulation. The water samples from boreholes and wells had high levels of dissolved oxygen (DO), pH, and heavy metals, particularly Pb²⁺ and Fe⁺, according to a physico-chemical examination. Analysis was made possible by mapping the GPS-measured locations of the fifteen sample sites onto the topography plan of the research region. WHO and NSDWQ, responsible for drinking water standards were contrasted with findings to determine any differences. The water sample has a "VI" grade on the Heavy Metal Index calculation scale, indicating a "Seriously Affected" water distribution mechanism, due to a substantial amount of heavy metals, especially Pb²⁺ and Fe²⁺.The study shows that in some areas, the flood water intrusion for physico-chemical parameters is predominant as evident in some of the samples as against others. This means therefore, that the flood water influences the physic-chemical, heavy metal and micro-biological concentrations of the groundwater quality of the affected areas, either through direct inflow into the water supply system, or through the process of elluviation.

Journal of Pollution Monitoring, Evaluation Studies and Control

Geospatial Analysis of Heavy Metal Intrusion in Groundwater Resources of Isoko North Local Government Area, Delta State, Nigeria

Environmental Impact and Physico-Chemical Analysis of Flood Water Intrusion in Domestic Boreholes and Well Water Quality in Isoko North Local Government Area and Environs in Delta State, Nigeria