This study investigated how pollutants, specifically those from landfill leachate, affect soil behavior. Clayey soil samples were artificially contaminated with varying amounts of leachate and subjected to consolidation tests. The research found that leachate significantly impacts soil properties. While consolidation rate increased, as indicated by higher coefficient of consolidation (Cv), the soil's compressibility and swelling potential decreased. This implies that polluted soils settle faster but are less prone to swelling. These findings underscore the importance of understanding pollutant effects on soil for accurate prediction of settlement and development of effective remediation strategies.