Landfill gases

Landfill gas is a mixture of gases produced by the decomposition of organic material in landfills[2]. The composition of landfill gas varies, but it typically contains 45% to 60% methane and 40% to 60% carbon dioxide by volume[3]. Other gases that may be present in smaller amounts include nitrogen, oxygen, ammonia, hydrogen sulfide, and volatile organic compounds[1]. Here are some important things to know about landfill gases:

• Methane: Methane is a flammable gas that is produced during the decomposition of organic waste in landfills. It is also a potent greenhouse gas that contributes to climate change[2].
• Carbon dioxide: Carbon dioxide is another greenhouse gas that is produced in landfills. While it is less potent than methane, it is still a significant contributor to climate change[2].
• Odors: Ammonia and hydrogen sulfide are responsible for most of the odors associated with landfills[1].
• Health concerns: Landfill gases can move through soil and collect in nearby buildings, where they can displace oxygen and create a risk of explosion or asphyxiation. Ammonia, sulfides, methane, and carbon dioxide are of most concern for human health[1].

To manage landfill gases, gas collection wells are installed throughout the landfill and are made of perforated pipes that allow the gas to move vertically to the surface rather than laterally towards off-site locations[1]. The gases collected can be vented into the outdoor air, passed through a flame and broken down by burning, passed through a filter, or used in an on-site combustion system to provide heat or generate electricity[1][4]. Landfill gas utilization strategies have been developed to reduce the amount of biodegradable content in municipal waste and to create landfill gas utilization strategies[4][5].

Citations:
[1] https://www.health.ny.gov/environmental/outdoors/air/landfill_gas.htm
[2] https://www.epa.gov/lmop/basic-information-about-landfill-gas
[3] https://www.atsdr.cdc.gov/hac/landfill/html/ch2.html
[4] https://en.wikipedia.org/wiki/Landfill_gas
[5] https://en.wikipedia.org/wiki/Landfill_gas_utilization
[6] https://www.colorado.edu/ecenter/2021/04/15/hidden-damage-landfills