Landfilling

Landfilling is a waste disposal method in which prepared waste is buried in engineered facilities called landfills. It is used for municipal solid waste and other non-hazardous wastes, while hazardous wastes require specially designed, permitted landfills with stricter controls. A modern landfill typically includes a bottom liner, a leachate collection and treatment system, daily and final covers, a gas collection network, and monitoring wells to detect leachate and gas migration.

Design and operation proceed through site selection, engineering design, and phased construction. Core features are a bottom liner to limit water infiltration, a leachate collection system to manage contaminated liquid, and a gas collection system to capture landfill gas, primarily methane and carbon dioxide. Daily cover controls odors, litter, and pests, while the final cap enables long-term stabilization. After closure, post-closure care and monitoring may continue for decades.

Environmental impacts depend on management quality. Leachate can contaminate groundwater or surface water if controls fail, and landfill gas is a source of methane emissions unless captured or utilized. Odors, pests, and aesthetic concerns may arise, especially near populated areas. These risks are mitigated by engineering standards, monitoring programs, and proper closure practices.

Regulation varies by country but generally requires liners, leachate management, gas collection, groundwater monitoring, and financial assurances for post-closure care. In the United States, MSW landfills are governed by Subtitle D of the Resource Conservation and Recovery Act; the European Union uses the Waste Framework Directive and national regulations.

Advantages include the ability to handle large volumes at relatively low upfront cost, while limitations involve long-term stewardship, space needs, and environmental risks. Alternatives and trends emphasize waste reduction, recycling, composting, mechanical-biological treatment, and waste-to-energy options to reduce reliance on landfilling.