Field based greenhouse gas emission measurement from onsite containments in Nepal

On-site sanitation systems (OSS) generate greenhouse gases (GHGs) during the decomposition of fecal matter. The reported measurements of these emissions are confined to a restricted number of research examining septic tanks in high-income nations. We conducted field measurements of onsite containments to generate emissions data for Nepal. This represents the first empirical investigation of greenhouse gas emissions from onsite containments in low- and middle-income countries. Emissions were recorded from a panel of pit latrines (n=18), holding tanks (n=6), septic tanks (n=3), between December 2021 and December 2022. A calibrated static flux chamber was designed was and deployed to collect gases samples at each containment site. Portable gas analyzers were employed to quantify methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O). Results will be provided in detail. Preliminary investigation showed a substantial range in emissions rates notably CH4 across different types of onsite sanitation containments. Statistical test indicated methane emission rates varied considerably within containment types (P value