Seasonal Dynamics and Leachate-Induced Alteration of Soils and Associated Risk of Surface Water Contamination Around the Hulene-B Waste Dump, Maputo, Mozambique

Waste dumpsites in developing countries are primary pollution sources impacting nearby ecosystems. This study assessed seasonal changes in soils surrounding the Hulene-B landfill (Maputo, Mozambique) and evaluated the potential for surface water contamination by leachates. A total of 71 samples were collected during the rainy and dry periods and analyzed for pH, electrical conductivity (EC), organic matter (OM), and color. The contamination potential (Pbci) was determined considering the landfill’s characteristics and local hydrological context. During the dry season, soils exhibited higher EC and OM, indicating greater retention of potentially toxic elements (PTEs) and a strong tendency for accumulation. In the rainy season, leaching processes prevailed, leading to reduced EC and OM but increased potential for contaminant mobility. The Pbci values were consistently high across both periods, confirming elevated contamination risk. Overall, the Hulene-B landfill exerts a marked influence on surrounding soils and nearby surface waters, underscoring the urgent need for structural measures to control leachate release and ash dispersion.