Landfill Odour

A landfill is a major diffuse and fugitive odour source, since it combines a large open working area with long-term anaerobic decomposition of buried waste. Because landfills typically operate for years or decades, odour management is an ongoing operational and community relations challenge rather than a one-time fix.

Odour intensity at a landfill varies significantly with weather, waste type, and how well gas and leachate are being controlled, which makes consistent characterization and control important for maintaining community trust.

Major Sources of Landfill Odour

• The active working face, where fresh waste is exposed before daily cover is applied
• Landfill gas escaping through cracks, cover breaches, or inadequate capping
• Leachate collection and storage systems
• Odorous waste streams such as biosolids, contaminated soils, or putrescible waste
• Gas collection and flaring or energy-recovery equipment malfunctions

Key Contributing Factors

• Waste composition and age, since fresh, biodegradable waste is more odorous than older, stabilized waste
• Cover soil type, thickness, and how frequently it is applied
• Weather conditions, particularly wind direction and atmospheric stability, which govern how odours disperse to nearby receptors
• Landfill gas collection system efficiency and coverage

Landfill Odour Control Strategies

• Prompt and adequate daily or intermediate cover application over exposed waste
• Active landfill gas collection paired with flaring or energy recovery
• Minimizing the size of the active working face
• Leachate management to reduce odorous storage and handling
• Biofilters or other treatment for odorous vent or process air streams
• Ambient monitoring and community odour complaint tracking to guide operational response

See Also

• Odour Source, for how landfill emissions fit within the broader classification of odour sources
• Fugitive Source, for gas migration through cover breaches
• Fugitive Release, for unintended releases such as pipe or cover leaks
• Diffuse Source, for emissions from the open working face
• Biofilter, for a common treatment technology for landfill process air
• For further technical background, see the ASTSWMO Odor Control at RCRA Subtitle D Landfills compendium.