Putrescible matter producing methane gas in landfills has caused explosions resulting in damaged property, caused injury and death. The danger may present from 10 to 20 years for any given site.
Landfill gas (LFG) is a natural byproduct of decomposing landfill waste. Without adequate controls, LFG can pollute the environment surrounding a landfill. In addition to emitting directly into the atmosphere, the gas can percolate through surrounding soils, penetrating nearby buildings and affecting vegetation growth.
Landfills were the number one source of Canadian emissions of methane in 1990 - 38% of a total of 3.7 megatonnes.