landfill

A landfill is a waste disposal facility where waste is isolated from the surrounding environment by engineered barriers and managed to control byproducts such as leachate and gas. It is a common method for disposing of municipal solid waste and is designed to minimize releases to soil, groundwater, and air.

Key features of modern landfills include a liner system, typically a composite of synthetic and clay components, to prevent leachate from entering the ground. A leachate collection and treatment system removes contaminated liquid. The waste is placed in cells and covered daily or periodically to limit odors, pests, and wind erosion. A landfill gas collection system captures methane and other compounds produced during decomposition, often for flaring or energy recovery.

Waste undergoes progressive stabilization as it decomposes under largely anaerobic conditions. Methane, a potent greenhouse gas, is a major target for capture and use in energy projects. Final cover systems, drainage, and erosion controls are installed at closure, followed by long-term monitoring and maintenance to manage potential leachate and gas emissions and to ensure structural stability.

Landfills vary by type and regulatory regime. Municipal solid waste landfills receive everyday household and commercial waste, while construction and demolition landfills handle inert materials from building projects. Hazardous waste landfills and industrial waste facilities operate under stricter containment and monitoring requirements. Regulatory frameworks—such as permits, design standards, and closure obligations—aim to minimize environmental and public health risks. In many systems, waste reduction through recycling, composting, and waste-to-energy alternatives is pursued alongside landfill disposal.