The linked article indicates that while the EPA is working to improve their methane emission accounting methodology; they are still underestimating such emissions:
https://www.sciencenews.org/article/epa-underestimates-methane-emissionsExtract: "The U.S. Environmental Protection Agency has a methane problem — and that could misinform the country’s carbon-cutting plans. Recent studies suggest that the agency’s reports fail to capture the full scope of U.S. methane emissions, including “super emitters” that contribute a disproportionate share of methane release. Those EPA reports influence the country’s actions to combat climate change and the regulation of methane-producing industries such as agriculture and natural gas production.
With EPA’s next annual methane report due to be published by April 15, early signs suggest that the agency is taking steps to fix the methane mismatch. A preliminary draft of the report revises the agency’s methane calculations for 2013 — the most recent year reported — upward by about 27 percent for the natural gas and petroleum sectors, a difference of about 2 million metric tons.
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EPA’s reports don’t just misjudge the scale of emissions, they also miss the long-term trend, recent work suggests. EPA reported that U.S. methane emissions remained largely unchanged from 2002 to 2014. But researchers report online March 2 in Geophysical Research Letters that emissions of the greenhouse gas rose more than 30 percent over that period. The United States could be responsible for as much as 30 to 60 percent of the global increase in methane emissions over the last decade, the study’s authors conclude. “We’re definitely not a small piece of that pie,” says Harvard University atmospheric scientist Alex Turner, who coauthored the study."
