Effect of dumpsite on groundwater quality: A case study of bonny island rivers state

Abstract

This study investigates the effect of dumpsite activities on groundwater quality in Bonny Island, Rivers State, Nigeria. Bonny Island, an ancient coastal city with significant economic importance due to its oil and gas industries, faces potential environmental threats from dumpsite activities. The research utilized vertical electrical sounding (VES) and 2D resistivity profiling (ERT) to assess subsurface contamination. Measurements were taken to determine the lateral and vertical spread of contaminants at the dumpsite. Complemented by laboratory analysis of groundwater samples from the two dumpsites, groundwater samples were analyzed for a range of physical, chemical, and biological parameters, such as pH, TDS, TSS, DO, Nitrates, Sulphates, Chlorides, heavy metals, and other pollutants. Results obtained indicate that the groundwater near the dumpsites exhibits varying levels of contamination. The VES and ERT profiles revealed low resistivity zones at shallow depths, indicating possible clay-rich soil or topsoil contamination from leachate. High resistivity areas in the middle depths suggest cleaner zones, but low resistivity at both ends of the profiles indicates further spread of the leachate. Laboratory analyses of groundwater sample showed that most parameters were within acceptable limits set by WHO and NSDWQ, except iron, which exceeded the permissible limit, suggesting contamination of iron at the site. These findings highlight the need for continuous monitoring and remediation efforts to prevent further deterioration of groundwater quality. This study underscores the critical importance of protecting groundwater in economically vital and ecologically sensitive regions like Bonny Island.