Methane (CH4) and carbon dioxide (CO2) are landfill gas (LFG) originating from the decomposition of organic material as encountered in landfill areas. Both are also considered greenhouse gas due to their high propensity in absorbing and emitting infrared radiation. For this reason, landfill installations are often equipped with wells and pumping systems to collect these LFG. Depending on the quality of the gas mixture, the gases might turn out to be collected, flared or simply dispersed in the atmosphere through passive methane vents. In some situations, gas leaks may occur on the site. In such circumstances, the wells, the tubing system or landfill liner integrity might be responsible for the undesirable methane emanations on site. In the case where lateral migration occurs, the gas leaks may even occur on properties located in the landfills’ neighborhood. These situations are difficult to address since large areas need to be surveyed. Several gas measurement techniques are currently available. Gas sampling using pressurized canister vessels or bags provides accurate results, even at low concentrations, but is time consuming since the samples need to be taken into a lab. Electrochemical cell sensors, also known as gas sniffers, provide accurate real-time results. Conventional gas measurement techniques typically provide single-point results and their use to locate an unknown gas leak within such large area is not suitable. In order to illustrate how thermal infrared hyperspectral imaging performs in landfill environments, results from diffuse methane emissions are presented. Real-time chemical imaging results, carried out on a passive methane vent, are also presented. The results illustrate how thermal infrared hyperspectral imaging systems provide valuable information to survey methane gas in landfill areas.
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