Leachate Pollution Index: An Assessment and Treatment Strategy Designing Tool for Landfills

Landfilling has been considered the most conventional, efficient, and cost-effective waste management technique for developed and developing nations. Traditionally, open dumping has been practiced in India for ages as a simple waste management solution which has now been gradually replaced by sanitary landfilling. Leachate, a seepage liquid percolated from both landfills, is a toxic cocktail of different industrial chemicals, heavy metals, micro and nanoparticle waste, and microbial metabolic products that make it a potential environmental threat. Leachate Pollution Index is a comprehensive tool for assessing and characterizing landfill leachate in terms of its pollution potential. The present study assesses the quality of leachate from both sanitary and open landfill in a typical urban environment under a tropical climate to understand the requisite rationale to identify potential treatment strategies using the leachate pollution Index as a tool. Samples were collected from an unlined open dump and a sanitary landfill site in West Bengal. Leachate pollution was assessed based on its physicochemical properties (BOD, COD, phenols, total coliforms, nitrogen, total dissolved solids (TDS), chlorides, and heavy metals) as per APHA standards. The cumulative leachate pollution potential due to organic, inorganic, and heavy metal components was reported in terms of the Leachate Pollution Index (LPI). LPI values for both sites were observed to be in the range of 12–24 units, significantly higher than the standard discharge limit (LPI ≤ 7.4), and hence they can be termed as a potential environmental threat that needs immediate attention before releasing to the environment.