Leachate pollution from a dumpsite: environmental health impact and proposed control measures in Bahir Dar City, Ethiopia

Abstract

Groundwater is a critical resource for drinking and irrigation, particularly in the Blue Nile River Basin, Ethiopia. However, uncontrolled waste disposal and leachate leaching from dumpsites can severely compromise water quality. This issue is not unique to Ethiopia. Globally, leachate from poorly managed landfills poses a serious threat to groundwater. This study investigates the impact of a dumpsite on shallow groundwater contamination in Bahir Dar City, assessing the associated risks to nearby communities. Groundwater and leachate samples were collected and analyzed using standard protocols to determine their chemical and physical properties. The Leachate Pollution Index (LPI) was applied. It quantifies the leachate contamination potential based on the concentration of 18 parameters and can be adopted even if data is not available for all the parameters. Results were compared with national and international water quality standards. Groundwater level maps and subsurface flow directions were generated using Surfer 2.0 software. The LPI value of 42.11 indicates a relatively high pollution risk. Among the heavy metals, chromium emerged as the most concerning contaminant, due to its toxicity and bioaccumulation potential. As expected, W1, being the closest well downstream to the dumpsite, was a hot spot with the highest concentrations of pollutants. Surprisingly, W6, i.e. the closest well upstream the dumpsite, was the second more polluted well. This result suggests complex hydrogeological dynamics or site-specific conditions that deserve further investigations. The study highlights the urgent need for improved waste management and groundwater protection strategies. Its integrated monitoring and inferential approach offers a replicable model for addressing similar challenges in other regions facing rapid urbanization and inadequate waste infrastructure.