Current Research on Geography, Earth Science and Environment Vol. 9

Open waste disposal systems have raised significant environmental concerns because of their potential to degrade soil quality. This study assessed the effects of waste dumpsites from auto mechanic (A), abattoir (AB), and paint processing (P) activities on soil quality. A control area (C), with no known waste contamination, was selected for comparison. Soil samples were collected from three depths (0-20, 20-40, and 40-60 cm) at the dumpsites after (waste removal) and at the control site, and were analyzed using standard laboratory methods. Soil quality indicators associated with nutrient availability, namely soil texture, pH, organic carbon (OC), and total exchangeable bases (TEB), as provided by the Harmonized World Soil Database (HWSD), were used for quality assessment. The results showed that waste deposits significantly altered the physicochemical properties of the soils. Particle size distribution analysis indicated that the soils were predominantly sandy, consistent with their coastal plain sand origin. The pH values of the impacted soils increased to 7.36, 7.99, and 6.49 for A, P, and AB, respectively, compared with 4.63 for C, indicating a shift from acidic to near-neutral (AB) and alkaline conditions (A and P). OC levels were significantly higher in A and AB, suggesting organic matter accumulation; however, these elevated levels may not necessarily indicate improved soil fertility because of possible contamination and low-quality organic residues. Positive correlations between measured indicators in waste materials and impacted soils demonstrated the influence of waste composition on soil properties. The study concludes that open dumpsites negatively affect the soils they occupy, reduce soil quality, and pose risks to agricultural and environmental sustainability. Engineered landfills and eco-friendly remediation techniques, such as phytoremediation, are recommended.