FFPs relative to total emissions from cities in the U.S. Midwest such as Chicago (69.5%) and Indianapolis (57.3% ± 18.8%) fall somewhere between estimates for U.S. west and east coast cities. One measurement performed in June 2017 with a low FFP (26.7%) lowered the mean for Indianapolis , whereas other studies measured higher FFPs for this city . The South Side Landfill in Indianapolis has been characterized in several studies and is estimated to account for up to ~35% of the city's total CH4 emissions. measured CH4 from a stationary sensor network across Indianapolis and used the posterior footprint of an atmospheric inversion to estimate that biogenic emissions account for 48% of the city's total emissions. Other landfills are located on the urban fringe of Indianapolis; depending on the domain sampled, these or other biogenic sources may be contributing to the remaining biogenic CH4 emissions that cannot be attributed to the South Side Landfill . If no other landfills contribute to the 48%, then wastewater collection and treatment or other biogenic sources such as wetlands may account for up to 13% of total CH4 emissions in Indianapolis.