Assessing groundwater contamination near dumpsites in port Harcourt using water quality index (WQI): insights from seasonal and distance-based variations

Rationale: Groundwater contamination poses a significant public health risk, particularly in urban areas with inadequate waste management. Dumpsites serve as major sources of pollutants, including heavy metals, which infiltrate aquifers through leachate migration. Port Harcourt, Nigeria, faces increasing groundwater quality concerns due to the proliferation of uncontrolled waste disposal sites. Objectives: This study aims to evaluate the spatial and seasonal variations in groundwater quality around dumpsites in Port Harcourt and determine the suitability of groundwater for drinking based on WQI values. It also seeks to identify contamination patterns and assess the influence of rainfall on pollutant dispersion. Furthermore, the study compares findings with global research to establish broader implications for waste management and public health. By doing so, it provides a scientific basis for policy recommendations aimed at mitigating groundwater pollution. Methods: Groundwater samples were collected from various locations around major dumpsites in Port Harcourt during dry and rainy seasons. Physicochemical parameters, including heavy metal concentrations, were analyzed to compute WQI values. Comparative analysis with previous studies was conducted to validate observed contamination trends. The impact of leachate migration on water quality was assessed using seasonal variations in WQI values. Results: Findings reveal significant spatial and seasonal fluctuations in groundwater quality. While Choba exhibited excellent water quality, Sasun, Rumuolumeni, and Epirikom recorded dangerously high WQI values, indicating unsuitability for drinking. Seasonal variations showed that rainfall exacerbated contamination levels, as seen in Eleme, where WQI increased from 56.362 in the dry season to 140.928 in the rainy season. The study aligns with previous research from India, China, and Ghana, demonstrating that landfill leachates and surface runoff are key contributors to groundwater degradation. Conclusion: The study confirms that dumpsite leachates significantly impact groundwater quality, posing a major risk to public health. The high WQI values in several locations highlight the need for urgent interventions. Findings align with global research on groundwater contamination, emphasizing the critical role of effective waste management in reducing environmental pollution. Recommendation: To mitigate groundwater pollution from dumpsite leachates, it is essential to implement stringent waste management policies that regulate landfill operations and prevent leachate infiltration into aquifers. Establishing continuous groundwater monitoring programs can help detect contamination trends early and guide timely intervention measures. Additionally, promoting alternative potable water sources in highly contaminated areas is crucial to reducing health risks for affected communities. The adoption of modern landfill technologies, such as leachate treatment and containment systems, should be prioritized to minimize pollution and safeguard water resources for future generations. Significance statement: This study contributes to the growing body of research on groundwater contamination by providing empirical evidence of the impact of dumpsites in an urban African setting. The findings underscore the urgent need for improved waste management policies and public health interventions. By aligning with global research, this study reinforces the importance of sustainable environmental practices to safeguard water resources and protect communities from the adverse effects of pollution.