Mostyn Wall, Natural Resources Wales, explores how the Landfill Emission Reduction Project is enabling Wales to meet its national carbon reduction targets.
Methane emissions from landfill remain one of the most significant climate challenges facing the waste sector. Wales has made major strides in reducing biodegradable waste to landfill through waste prevention, recycling and the transition towards a circular economy; however, landfill sites continue to generate landfill gas for decades after biodegradable waste is no longer landfilled.
Ensuring that this gas is effectively captured and managed is therefore critical to meeting national carbon reduction ambitions.
The Landfill Emission Reduction Project (LERP), funded by the Welsh Government, was established by Natural Resources Wales to address this challenge through a combination of technical audits, improved emissions reporting and investment in gas management infrastructure.
The project is demonstrating how targeted intervention can achieve measurable reductions in methane emissions while improving environmental regulation and operational performance across the landfill sector.
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A key focus of the programme has been improving the quality of landfill gas data input into the model that produces landfill emissions for the National Atmospheric Emissions Inventory (NAEI). Early project work identified inconsistencies and gaps in reporting across several Welsh landfill sites, particularly where facilities had closed or relinquished its environmental permit.
By working directly with operators and reviewing historical records, LERP significantly expanded the volume of available emissions data reported and improved the accuracy of the NAEI. Accurate reporting of landfill gas captured and destroyed in an engine or a flare reduces the amount of methane assumed to be released to the atmosphere.
As a result, the number of Welsh landfill sites reporting gas utilisation and flaring data increased from 17 to 30. Approximately 17 million cubic metres of landfill gas data, previously absent from national reporting systems, was identified and incorporated into the NAEI for 2021 to 2025. This equates to around 5,354 tonnes of methane, or almost 150,000 tonnes of carbon dioxide equivalent.
Using UK Government carbon valuation methodologies, the climate value associated with these emissions is estimated at around £37 million. The LERP project is now updating the historical submissions to the NAEI to fill in gaps in the database and reviewing the accuracy of Pollutant Release and Transfer Register (PRTR) submissions by comparing known landfill gas capture to the modelled releases of methane.
Alongside data improvement, LERP has undertaken detailed audits of operational and closed landfill sites throughout Wales. These assessments examined gas capture systems, flare performance, surface emissions, capping integrity and overall site management practices.
The audits identified a common set of issues, including damaged gas infrastructure, insufficient temporary capping and opportunities to improve gas collection efficiency.
One of the most notable examples was a large operational landfill, where audits identified substantial fugitive methane emissions alongside limited flare capacity and weaknesses in gas management infrastructure.
Following implementation of the project’s recommendations, including enhanced capping and installation of additional gas control measures, captured landfill gas volumes increased by approximately 46% between 2023 and 2024. The improvements also contributed to a significant reduction in odour-related complaints from neighbouring communities.
At several operational landfills, the project identified emissions from uncapped areas and leachate management systems. Relatively straightforward engineering interventions, including additional capping works, delivered measurable improvements in gas collection and reduced off-site impacts.
Gas capture increased following infrastructure improvements demonstrating how targeted actions can deliver significant environmental benefits even at established sites.
The audit programme has also helped identify sites requiring further regulatory attention. At closed landfills, inspections highlighted issues, including damaged gas infrastructure, extensive uncapped areas and deficiencies in maintenance regimes.
Findings from audits informed subsequent regulatory and enforcement activity, underlining the role that independent technical assessments can play in driving environmental compliance and operational improvement.
Not all findings were negative. Many operational and closed landfills emerged as examples of good practice, demonstrating the benefits of proactive site management, effective capping and robust gas control systems. These sites illustrate how operational discipline and ongoing investment can reduce emissions risks while maintaining compliance standards.
Beyond individual sites, the project has provided valuable insight into the condition and future management needs of landfill gas infrastructure across Wales. Many closed sites continue to produce gas but are experiencing declining volumes as waste decomposes.
This creates operational challenges as older flares, engines and extraction systems become increasingly costly to maintain while generating lower revenues from electricity production. LERP has therefore begun developing a national inventory of gas management assets, including flares, engines, boosters and monitoring equipment, to support future strategic planning and investment decisions.
The programme has also identified several historic landfill sites with either existing gas capture systems or future potential for methane recovery. Better understanding these assets will help inform future interventions and ensure that methane emissions from legacy waste disposal activities are minimised over the long term.
Looking ahead, LERP is exploring the use of advanced methane detection technologies to further enhance performance. Plans include deployment of optical gas imaging cameras capable of visualising methane emissions in real time, enabling operators and regulators to identify leaks more quickly and target remedial works more effectively.
The project is also investigating opportunities to use aerial and satellite monitoring technologies as part of a wider methane surveillance capability across Wales.
The success of LERP highlights several important lessons for the wider waste and resource management sector. First, accurate emissions reporting is fundamental to understanding the true scale of landfill methane emissions and the benefits of mitigation measures.
Second, relatively simple operational improvements, particularly enhanced capping, gas infrastructure maintenance and gas management plans, can deliver substantial reductions in fugitive emissions. Finally, effective collaboration between government, regulators and operators is essential if the remaining environmental impacts of landfill are to be managed successfully.
As Wales continues its transition towards a circular economy, reducing emissions from legacy landfill sites remains an important part of the journey to net zero.
The Landfill Emission Reduction Project demonstrates that targeted technical intervention, robust data management and a focus on continual improvement can deliver significant climate benefits.
By strengthening both operational performance and emissions reporting, the project is helping to ensure that landfill methane is identified, measured and controlled more effectively than ever before.
