Anaerobic Digestion remains the cornerstone technology for sewage sludge treatment, with a renewed effort to maximise recovery of biogas or biomethane to support UK’s water industry Net Zero targets. In parallel, biomethane is central to UK’s energy security and net-zero strategy, with the Department for Energy Security and Net Zero (DESNZ) enabling significant growth through the Green Gas Support Scheme (GGSS). Biomethane displaces fossil methane and valorises unavoidable wastes, including sewage sludge. However, fugitive methane emissions across the anaerobic digestion (AD) lifecycle compromise sustainability gains. Life cycle assessment showed that losses of 3–4% breach the carbon intensity threshold of 24 gCO₂e/MJ which the European Renewable Energy Directive II (REDII) sets for biomethane to be considered sustainable, while >10% render biomethane more carbon-intensive than natural gas. The DESNZ Methane Emissions from AD (MEAD) project revealed variability across UK gas-to-grid plants, recording 4–22% losses, driven by digestate storage (3–8%), AD leaks (0–13%), and upgrading slip (0.6–4%). The follow up Methane Emissions from AD 2 (MEAD 2), delivered by Alder Bioinsights in collaboration with Bohr and Marches Biogas, sheds further light on specific emission sources, with a further 8 full-scale UK sites monitored, including sludge treatment centres. The number of leaks across sites varied from 1 to 17, with leaks from the AD reactors and poorly maintained pressure relief valves as the most common source of leaks. Once leaks are addressed, emissions from digestate storage emerge as the biggest emission point across AD sites, with MEAD 2.0 investigating strategies for further abatement. This presentation will include findings from MEAD and the soon to be published MEAD 2.0, accounting for a total of 15 full-scale ADs monitored, as well as Cranfield research investigating what governs digestate emissions and how they differ for conventional and advanced AD sites.