This research work is an insight into the various properties of liner materials utilized in landfill sites to control the leachate. Although expansive clay soil is inorganic, it is problematic. The soil owes this aspect to erratic fluctuations in its behavior due to the movement of water. Urbanization, increase in population and industries generate enormous amounts of waste in different forms. Disposal of these wastes in the landfill without any scientific manner creates a major problem to the surrounding soil and groundwater. In this study, an attempt was taken to identify the effect of soil properties and groundwater quality due to the continuous generation of leachate in the dumping sites. To prevent such an environmental problem, highly impermeable sand–bentonite mixture is used as a liner material in the waste disposal sites. Therefore, various mixtures of sand–bentonite were prepared by varying sand contents and different sieve sizes, i.e. 2–0.075[Formula: see text]mm; 2–0.425[Formula: see text]mm and 0.425–0.075[Formula: see text]mm were used. And also to improve the strength and hydraulic conductivity of the liner materials, discrete random fiber is mixed with various proportions to these mixtures and examined.