Design of an engineered landfill as possible replacement for an existing dump at Akure, Nigeria

This work focuses on the design of an engineered (semi-aerobic) landfill in Akure with a view to encourage a shift from the use of a dumpsite, which despite its adverse environmental impact has remained the method of waste disposal in Nigeria. Topographic maps, population figures, per capita waste generation and laboratory geotechnical investigation provided some of the basis for the landfill design. The waste generation potential of Akure and the leachate generation and gas emission potentials of the landfill were estimated. The cumulative waste generation potential of the landfill over its 15 years life was estimated to be 5.89 × 106 m3 (2.18 × 109 kg) and the landfill will require a dimension of 935 m × 905 m × 10 m. The geotechnical tests revealed the proposed site will not yield under landfill loadings, while the hydraulic conductivity and consistency properties of the borrow pit soil samples show that they are suitable for use as liner materials. The design is composed of specifications for a liner, a capping system, leachate collection using a high-density polyethylene (HDPE) pipe system, gas capture and monitoring systems against leachate and landfill gas migration from the landfill. This research work will form readily accessible reference material for the design of engineered landfill in developing countries.