Manuscript: The National Implications of Adding Sewer CH4 and Methanol-Derived CO2 to Wastewater Treatment and Conveyance GHG Inventories

Sewer methane (CH4) and methanol carbon dioxide (CO2) have been poorly covered in greenhouse-gas (GHG) emissions protocols. Sewer CH4 in the developed world has been formally discounted by the IPCC (2006) and this approach has been adopted by all other protocols to date. Methanol, which is derived from natural gas and its conversion to CO2 therefore represents an anthropogenic emissions source, had been ignored until ICLEI’s US Protocol published their methodology WW.9 in 2012. This paper normalizes estimate for these two “new” GHG sources within the context of DC Water’s (Washington, DC) Blue Plains Advanced Wastewater Treatment Plant’s (AWTP) GHG inventory. These DC Water data are then used to estimate the national significance of these new sources.