Question

Explain how waste is disposed off in sanitary landfills.

Answer 1

1. Site Preparation and Lining: Low-lying areas or specially selected sites are lined at the base and sides with impermeable materials (such as thick clay or synthetic geomembranes) to prevent toxic liquid runoff from seeping into and contaminating the groundwater table.
2. Layering and Compacting: Solid waste is dumped into the site in thin layers, which are then heavily compacted using mechanical bulldozers and heavy machinery to reduce volume and maximize capacity.
3. Daily Soil Cover: At the end of each working day, a fresh layer of soil (usually 20 to 30 centimeters thick) is spread over the compacted garbage. This acts as a barrier to prevent foul odors, stop waste from scattering, and keep away disease vectors like flies, rats, and stray animals.
4. Leachate Collection and Treatment: As waste decomposes and mixes with rainwater, a toxic, highly contaminated liquid called leachate forms. A plumbing network of perforated pipes sits at the sloped bottom of the landfill to catch this fluid as it trickles down. The liquid is collected and pumped out to an on-site treatment facility or municipal sewage plant where it is safely decontaminated.