Landfill Gases: What Are They?
Landfill sites have been in the news for some time, but this is largely to do with the amount of waste that we put into them. However, a big concern should also relate to what is coming out of them again.
Landfill sites emit their own fumes which are made up of hundreds of different gases such as methane and carbon dioxide, which is not only harmful to the environment, but also to our health.
What is landfill gas?
As the biological materials in a landfill site such as rotting food begin to decompose with the help of bacteria, reactions between various chemicals such as ammonia can take place and turn into a vapour which is then released into the atmosphere.
This creates a gas made up of methane and carbon dioxide amongst other things and is causing both scientists and health professionals a great amount of concern.
What is landfill gas made up of?
Landfill gas is proving to be particularly worrying as it has been found to contain between 45% and 60% methane as well as similar amounts of carbon dioxide. There are also trace amounts of gases such as benzene, toluene, ethyl benzene and xylenes, which are not only toxic, but can form ozone and greenhouse gases when they react.
These greenhouses gases are known to be extremely damaging to the planet and can contribute to the raising of its temperature. Landfill gas has also been found to contain hydrogen sulphide, which can have a very detrimental effect on health.
The odours of these gases can be detected more than a mile away from any landfill site, and as methane can be as much as 34 times more effective at warming the atmosphere than carbon dioxide, it is particularly worrying that around 11% of the planet’s methane emissions comer from landfill gas.
How can landfill gases be used?
This gases are extremely powerful, which means that they can be put to good use as well as bad. Landfill gas wells are capable of collecting the gases that have been emitted and sending them for processing using a vacuum system.
The gas can then be flared and used as an effective source of energy that can then power nearby homes and businesses instead of polluting them.
Why does landfill gas need to be monitored?
It is important to monitor landfill gas closely, as it can have some huge consequences for the health of those living nearby. Symptoms can include headaches and burning eyes but can ultimately be far more tragic. Some areas have also reported low birth rate and birth defects. Some landfill gases can also form an explosive mixture which can be very dangerous.
This makes it imperative that the levels of landfill gases are carefully monitored, and this is done through a process called Surface Emission Monitoring (SEM). This uses a portable methane metre to measure the concentration of methane in the air around the site. This should be moved around to accommodate changes in wind direction and locate any particularly worrying pockets that might develop.
When you consider that landfill gas is dangerous to immediate human health as well as the health of the planet, it is clear that it not only needs to be closely monitored, but eliminated as well.
It poses a threat to those who live close to the site as well as to the wider planet. By collecting it and putting it to good use, it is possible to turn a potential disaster into a cleaner, cheaper form of energy that can actually benefit those around it instead of making them unwell.