In January 2025 EBNet supported a by-invitation workshop on GHG emissions in sanitation systems. The workshop was run by EBNet’s N2O WG in conjunction with Prof Barbara Evans and her team at the University of Leeds, and included participants from half a dozen countries. The focus was on measurement of GHG emissions and their relationship to the microbiological processes within sanitation systems, with the aims of sharing experience, mapping research efforts and promoting networking of researchers in this field.
Points made in discussion were the significance of on-site sanitation (OSS) and the whole sanitation chain in global emissions; the difficulty of interpreting of empirical data; and the lack of a full understanding of the microbiological processes and ecological characteristics that drive emissions.
It was noted that “Globally, on site sanitation (pits and tanks) are thought to be almost as large a source of GHG emissions as centralised Wastewater Treatment Plants. In the US and EU only around a quarter of the population are using these off-sewer systems, but they are widespread globally and will continue to be built over the coming 30 years. WWTP get built comparatively very rarely, so off-sewer systems offer significant scope for innovation”.
“OSS is sometimes regarded as ‘primitive’ but this is not the case in terms of the research needed, and the fundamentals are complex”.
Key research needs identified included:
- to study fundamental microbiology of OSS microbial communities
- to study fundamental physics
- 3D structure of key enzymes present in pit latrines
- a CFD model of a septic tank
- to understand what’s happening in soil systems re: sinks, sources of GHG emissions
- to understand space/time scales?
- to understand Immigration, growth, death – “the only factors that matter”
Now participants in the event are working together to apply datasets from one group to models developed by others – hopefully leading to new advances in our understanding of these complex challenging systems
The report on Measurement of Greenhouse Gases from Sanitation and their Relationship with Microbiological Processes within Sanitation Systems is available here, with a two-page Summary of some key points here.
For more information contact Prof Barbara Evans or Prof Tom Curtis, the N2O WG Lead.
Workshop photo courtesy of Dr Nopa Dwi Maulidiany, Universitas Indonesia
