2 Methane emissions are the second most prevalent greenhouse gas (GHG) after CO 2 , with a global warming po- tential (GWP) that is 86 3 times higher than CO 2 , over a 20-year time frame. Accurately quantifying these emissions stands as a fundamental prerequisite in the pursuit of eective methane emission reduction policies. The natural gas system is the second largest anthropogenic source of methane in the U.S., spanning from production and processing to transmission and distribution.