Suitability of Laterite Soil to be used as a Landfill Liner Material from Oluku Dumpsite in Benin City, Edo State, Nigeria

Abstract

The objective of this paper was to assess the suitability of laterite soil to be used as a landfill liner material from Oluku dumpsite in Benin City, Edo State, Nigeria. Laboratory investigations were conducted to determine key geotechnical and hydraulic properties, using various standard methods in relation to landfill liner requirements. The data obtained indicate that some parts of soil exhibit low plasticity, while others exhibit high plasticity (Plasticity index (PI) ranged approximately from 10 to 40% and liquid limit (LL) ranged approximately from 25 to 58%), compaction characteristics (MDD = 1.82 to 1.88 g/cm³; OMC = 11.2 to 12.8%), angle of internal friction ranged from 3.12 to 6.53°, and cohesion values ranged from 10 to 27 kN/m². The hydraulic conductivity ranged from 0.71 x  to 2.89 x m/s. Alongside the main objective of this study the ability of laterite soil to reduce the migration of contaminants into the groundwater system was also assessed. This study was motivated by the need to evaluate a locally available and cost-effective alternative to geosynthetic liners, particularly in this area where the community relies on groundwater resources for domestic use. Following the assessment of laterite soil obtained from this area, recommendations were provided based on the findings.