We Contribute to Scientific Article on Methane Emissions
A reliable understanding of methane losses at wastewater treatment plants is essential for achieving effective reductions. Together with utilities in England and Australia, Aarhus Vand describes methods and results from methane measurements in a newly published article in Water Research X.
New evidence shows that methane emissions may be underestimated in practice. We have collaborated with Severn Trent in England and Melbourne Water in Australia to contribute to this scientific publication.
“Knowledge about measurement methods, uncertainties, and results is crucial for reducing methane emissions. In this article, we have consolidated our insights so others can benefit from them,” explains Morten Rebsdorf, Senior Project Manager at Aarhus Vand.
The article provides insights into measurement techniques, including tracer gas, LIDAR, satellites, and optical gas imaging.
Methane Losses Are Underestimated by a Factor of 1.5
In short, the conclusion is that methane (CH₄) emissions from wastewater treatment plants are significantly more variable and often higher than what is reported using generic emission factors. Measurements show that actual emissions may be underestimated by a factor of 1.5. Aarhus Vand has used tracer-gas methods to analyse methane leaks at the Egå and Marselisborg treatment plants.
“In Denmark, we currently use an emission factor of 1.3% — but in reality, it is closer to 7%. This demonstrates the need for more knowledge to obtain an accurate picture. With the right insights, we can better prioritise our efforts as a climate-conscious utility or as an energy authority,” says Morten Rebsdorf, Senior Project Manager at Aarhus Vand.
Accurate Measurements Support Methane Reduction
The study shows that robust and targeted monitoring is essential for effectively reducing methane emissions. The results highlight the need for more consistent, measurement-based reporting methods and for strategic investments in modernising sludge treatment processes and ageing infrastructure. By integrating accurate measurement, targeted initiatives, and regulatory support, the water sector can significantly reduce methane emissions.
The article is the result of 18 months of work and was published in January 2026 in Water Research X as a peer-reviewed scientific article. The article is open access and can be accessed here: Methane emission monitoring at wastewater treatment plants in Europe and Australia