The Use of Lateritic Soils as a Cover Material in Municipal Solid Waste Landfills in Nigeria

Abstract

Classification tests were undertaken on lateritic soils ( Soil A, Soil B, Soil C, Soil D) obtained from four borrow pits near the main waste dump being used for the disposal of municipal solid waste (MSW) produced by the residents of Ado Ekiti, Nigeria. Classification according to BS 5930 indicated the soils as clayey SAND (clay of intermediate plasticity). Using AASTHO classification system, Soil A and Soil C were classified as soil type A-2-6 and Soil B and Soil D were classified as soil type A-2-7. The effectiveness of different soil types used as cover material were rated and the different functions of the cover materials in a landfill were ranked according to their perceived importance. Overall rating of the performance of each soil as daily cover and as intermediate cover were obtained from the mathematical computation using the ranking and rating of each soil. The results show that the lateritic soils tested in this study are good as intermediate cover. Although the lateritic soils appear to be fair as a daily cover, it may be used if the clay content is excluded as much as possible.

Keywords: daily cover, intermediate cover, lateritic soil, municipal solid waste landfill, rating, ranking.