Solid waste disposal on land is a common and widely utilised method in many parts of the world. One of the drawbacks of this method is the generation of leachate which may contaminate the ground water. Generally, the contaminants are released from the solid waste to the ground water through physical, chemical, and microbial process. Estimation of leachate rate in a landfill site is an important step in designing the collection system or identifying the treatment alternatives to reduce the migration of pollutant from the leachate to both surface and subsurface water. Several models using hydrologic water balance techniques to predict the leachate volume at the landfill bottom have been developed. The movement of leachate through the solid waste depends upon the physical characteristics of the solid waste like mass density, porosity etc., and the composition of the materials such as organic and inorganic materials. Lumped Landfill Leachate Production (LLLP) model for landfill leachate, is described in this paper. Comparison of the results obtained using LLLP model, is made with those obtained from Hydrologic Evaluation of Landfill Performance (HELP) and Flow Investigation for Landfill Leachate (FILL) models. Samples from Perungudi Solid Waste Dumping Yard of Chennai are taken for the above models and are used to estimate the leachate quantity. The results indicate that the leachate quantity estimated from LLLP model is very close to the experimental results.
landfill, leachate, hydraulic gradient, moisture distribution, water balance models
