Suitability of using borrow pit soils collected from Southwestern Nigeria as landfill liners

Effective waste disposal system is essential in preventing the infiltration of leachate into the groundwater and in achieving the sustainable development goal of ensuring clean water. One of the ways to provide an adequate disposal system is through the provision and use of engineered landfills for waste containment instead of open dumps. Consequently, this study evaluates the suitability of using soils from six borrow pits collected from six states in Southwestern, Nigeria. To assess the suitability of the soils, laboratory tests were carried out to determine the index properties, mechanical and hydraulic properties of the collected soil samples. The results showed that the soil samples collected from the selected borrow pits in Ogun, Oyo and Ekiti States could be effectively employed for the containment of inert waste. In contrast, the soil samples collected from the selected borrow pits in Osun, Lagos and Ondo States needs to be improved such that their unconfined compressive strengths satisfy the standard requirement (≥200 kN/m 2 ). This study provides readily accessible soil data for use by engineering professionals involved in selecting suitable soil for use as landfill liners in Southwestern, Nigeri.