Screening method to assess the greenhouse gas mitigation potential of old landfills, based on downwind methane concentration measurements

A nationwide effort is taking place in Denmark to mitigate methane emissions
from landfills, by using biocovers. A large number of older landfills were found to be potential candidates for biocover implementation, but very little information was available for these sites to help evaluate if significant methane emissions occur. To assess these sites, we developed a low-cost and quick remote sensing methodology, whereby downwind methane concentrations from 91 landfills were measured using a mobile analytical platform, and emission rates were calculated using an inverse dispersion model. The method was found useful in gauging whether the sites were relevant for biocover implementation or not. The method is considered a screening technique, and alternative approaches such as the tracer gas dispersion method must be applied for emission quantification.