Measuring Landfill Methane Emissions

Challenge

Landfill methane emissions represent a significant climate risk, accounting for a substantial proportion of the UK’s greenhouse gas output. Methane is far more potent than carbon dioxide in the short term, making effective landfill gas management critical to achieving net-zero targets. Regulators and operators face a long-standing challenge: whole-site methane emisasions are difficult to measure accurately and consistently. The available monitoring approaches do not always provide confidence that landfill gas capture systems are performing as intended and can’t reliably measure the amount of methane that escapes. Without reliable measurement, it is difficult to benchmark site performance or design fair, evidence-based regulation to manage and reduce loss of methane into the atmosphere. The Environment Agency required robust, real-world data to inform future regulatory approaches to managing and mitigating methane from landfills.

Approach

Ricardo was commissioned by the Environment Agency to lead a comprehensive landfill methane measurement project. Working with the University of Southampton and the University of Manchester, the team evaluated two advanced methane monitoring techniques: the Tracer Dispersion Method (TDM) and the Unmanned Aerial Vehicle (UAV) mass balance method. Both techniques were deployed across four operational UK landfill sites under a range of operating and meteorological conditions. In parallel, Ricardo collected and analysed operator data from landfill gas collection systems to provide operational context. The project integrated methane emissions monitoring with meteorological measurements to investigate the effectiveness of the measurement techniques, and how operational conditions and weather influences emission rates.

A key focus was identifying metrics that could assess landfill gas management performance across different sites. The team developed and tested Methane Collection Efficiency (MCE) as a practical indicator that could be used across sites. Survey design, access constraints and methodological uncertainty were carefully managed to ensure scientific robustness. UAV surveys were also used to explore novel insights into methane slip from landfill gas engines. Close collaboration with regulators, site operators and academic partners ensured that the study findings were practical and policy relevant.

Outcomes

The project demonstrated that both TDM and UAV mass balance methods can effectively quantify whole-site landfill methane emissions, with each offering complementary strengths. Methane Collection Efficiency emerged as a credible performance metric, with measured values ranging from 52% to 99%, with variations linked to operational and weather and conditions. The findings showed that MCE is a useful indicator of changes in landfill gas management performance and could support future regulatory benchmarking.

The project provides a strong evidence base to support smarter methane regulation, improved landfill gas capture, and accelerated progress towards climate and net-zero goals. The final report has been published and is available here: https://www.gov.uk/government/publications/landfill-methane-measurement-and-metrics.

The project team is building on this project to carry out further measurements and integrate with wider Environment Agency and Defra research programmes.