Quantification of methane emissions from urban sewer network

Sewer systems, which consist of wastewater treatment plants (WWTPs) and sewer networks, are important urban water infrastructure that helps to improve water quality and prevent flooding. While they are recognized as a major source of methane emissions with considerable potential, accurate quantification of methane emissions from sewage systems has not yet been achieved. Here, we measured atmospheric methane from the urban sewer network using a mobile laboratory, which consists of the electric vehicle and monitoring instruments for Greenhouse Gas (GHG) such as carbon dioxide (CO2), methane (CH4), and ethane (C2H6). The mobile measurements of sewer networks are conducted in Gwanak district of Seoul in South Korea from September 2022. More than 3,000 manholes and rain gutters in commercial and residential areas were measured for the methane emissions of the combined sewer network type in Gwanak district. The methane emissions from urban sewer network were found to be significant in the study area. However, these emissions are currently not included in the national GHG inventory. Further details of our findings will be introduced at the European Geosciences Union (EGU) General Assembly 23.   This work was supported by Brain Pool Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT (No.2019H1D3A1A01101988)