landfill (sanitary landfill)

A landfill is an engineered land-based waste disposal facility where solid waste is deposited in discrete cells, compacted by heavy machinery, and progressively covered with daily, intermediate, and final soil layers to control odour, fire, vermin, and leachate. Modern engineered landfills are vastly different from open dumps — they incorporate composite bottom liners, leachate collection systems, landfill gas extraction, groundwater monitoring wells, and post-closure care plans — and are the regulated end point for non-recyclable, non-recoverable waste across every waste sector in India.

Indian landfill design and operation are governed by:

• Solid Waste Management Rules, 2016: under the Environment (Protection) Act 1986, set municipal landfill standards.
• Hazardous and Other Wastes (Management and Transboundary Movement) Rules, 2016: govern hazardous waste landfills.
• CPCB Technical Guidelines for Sanitary Landfills: prescribe siting, liner design (HDPE 1.5-2.0 mm over compacted clay), leachate management, and gas extraction.
• Plastic Waste Management Rules, 2016: prohibit landfilling of certain plastic wastes recoverable under EPR (Extended Producer Responsibility).

For CBG, plastic recycling, e-waste, tyre pyrolysis, and battery recycling sectors, landfill remains the disposal pathway for process residues that cannot be re-used:

• CBG plants: grit, inert residues from screening, occasional spoiled digestate batches.
• Plastic recycling: contaminated sortable fractions, multilayer films, fines.
• E-waste: glass cullet from CRTs (with lead immobilisation), plastic housings with brominated flame retardants.
• Pyrolysis: char residues (often beneficially used in road construction or sold as carbon black substitute, avoiding landfill).
• Battery recycling: slag from pyrometallurgical processing, immobilised contaminated soils.

The trade-off in landfill use is cost versus environmental impact. Engineered landfills with double liners, gas extraction, and 30-year post-closure care cost 800-2,500 INR per tonne disposed; uncontrolled dumping costs 50-200 INR per tonne but generates uncontrolled methane (28-36 GWP), groundwater contamination from leachate, and air pollution from spontaneous fires. Indian waste-sector economics — particularly the SATAT-aligned CBG sector and EPR-driven plastic recovery — are increasingly designed around landfill diversion: every tonne of organic waste diverted from landfill avoids 60-120 kg CO2e of methane emissions, creating monetisable carbon credit revenue. National Mission for Clean Ganga and the Swachh Bharat Mission both prioritise legacy landfill remediation, which is gradually expanding the corporate market for waste-processing services.