With a 20-year global warming potential (GWP-20) of 80 times the potency of carbon dioxide, reducing process emissions from methane leaks and area source emissions from bioresources facilities is a key priority for progressive utilities. However, measuring methane at WRRFs is challenging - to date methods have focused on short term efforts which only give a snapshot of emissions from process unit and area sources. Capturing seasonality and sporadic emissions are a challenge, as is measuring post digestion diffuse emissions from biosolids handling and storage. The role of multiple measurement and modelling approaches to support 'sufficient' quantification and the understanding of uncertainty across different methods and areas of ongoing improvement are key considerations for both quantification and mitigation.

Drawing on work in the UK and Canada, this paper will provide an overview of work to date by Metro Vancouver and project partners in measuring methane emissions at a large WRRF and discuss results and learnings to date. The paper will compare and contrast measurement methods and discuss their applicability to key sources. It will show how global experience to date can inform sufficient utility level measurement and mitigation approaches and how such learning can contribute to development of a National Monitoring Programme to support sector and country-level improvements. .