The use of scrap-tire-shreds as leachate collection layer in landfills would reduce the magnitude of the current tire disposal problem by converting a waste into a beneficial material. Laboratory studies were conducted to investigate scrap-tire-shreds as an attractive potential alternative to conventional gravel in the drainage layer of leachate collection system by comparative analysis of various physico-chemical parameters. Gravel and scrap-tire-shreds in combination were used as leachate collection layer. Laboratory Test Cells consisting of different combinations of scrap-tire-shreds (size range length = 25.4 mm to 76.1 mm and width = 5 mm) and gravel (size range 10 mm to 20 mm) beds as leachate collection layer with total bed thickness of 500 mm were constructed. Performance study of Test Cells-1 to 7, having different combinations of scrap-tire-shreds and gravel bed thickness, were studied to work out the best combination. Combined beds of scrap-tire-shreds and gravel gave better results as compared to conventional gravel or scrap-tire-shreds bed when used singly.Test Cell -3 having scrap-tire-shreds layer (200 mm) and gravel layer (300 mm) gave the best results in terms of percentage reduction in various physicochemical parameters of leachate. The reduction was as high as 68.8 and 79.6% in case of Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) values respectively. Further, three more laboratory Test Cells-8, 9 and 10 were constructed having scrap-tire-shreds and gravel layer ratio same as that of Test Cell-3 (best combination) but having scrap-tire-shreds of different widths 10 mm, 15 mm and 20 mm to find out the most suitable size. Bed of smaller size scrap-tire-shreds (5 mm) gave better results in comparison to bigger sizes. Leachate sample after passing through combined beds of scrap-tireshreds and gravel gave better results in percentage reduction in various physico-chemical parameters of leachate as compared to conventional gravel or scraptire-shreds bed when used singly.

Leachate generated from municipal solid waste landfill site affects the groundwater quality in the adjacent areas through percolation in the subsoil. In this study, Aggregate Index method is applied to determine the quality of groundwater around a municipal solid waste dumping site. As the aggregate index is an increasing function of the distance from the landfill site, the groundwater quality improves as one move away from the landfill site. Aggregate index decreases with increase in time. Thus, water quality goes down with time. It may be due to the reason that with the passage of time the solid waste material gets degraded and the waste constituents percolate down along with rainwater thereby polluting groundwater. Hence, some remedial measures are required to prevent further contamination of groundwater in the vicinity.

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