New Data Shows 'Super-Emitter' Oil and Gas Pollution across the Appalachian Basin, Unknowingly Impacting Communities

The Environmental Protection Agency defines a super-emitter event as a release of methane with an emission rate of 100 kilograms per hour/220 pounds or greater

A new report from the Gas Leaks Project and Earthworks found nearly 100 oil and gas emission events in the Appalachian Basin, which cumulatively were observed emitting an estimated rate of more than 162,000 pounds of methane per hour, unknowingly exposing nearby communities to harmful carcinogens. These super-emitter incidents were observed from 70 oil and gas sources, based on one year of data across Pennsylvania, Ohio, and West Virginia. The report identifies the companies likely responsible for over half of the detected plumes, including those from corporations that claim to be leaders in methane reduction.

“When we started working on the analysis, we assumed the companies that’ve most prominently detailed their methane reduction plans would have the fewest plumes. We were surprised to find the opposite,” said Geoff Bromaghim, Director of Methane Accountability for the Gas Leaks Project. “The current system of self-reporting emissions is broken. We have all the technology and tools, but these companies won't regain the public's trust until they can actually prove they are being good neighbors and use them.”

The analysis relies on aerial and satellite data collected on Carbon Mapper’s portal from November 1, 2024, to November 2025 across the gas-producing regions of the Appalachian basin. The report also cross-referenced the ninety-six plumes with PSE Healthy Energy’s Methane Risk Map (MRM). Benzene, a known carcinogen, is linked to a range of detrimental health effects, such as cardiovascular disease, diabetes, lung cancer, and leukemia, and recent research has found that exposure to air pollution may directly increase the risk for Alzheimer's disease and exacerbate certain mental health disorders, including anxiety and Schizophrenia.

Key Findings:

• The team was able to identify likely sources by company for 59% of these plumes
• Of the 70 oil and gas methane plume sources, 16 (23%) were detected polluting on multiple days
• Nearly 30% (20 sources) appeared to be polluting every day they were observed over the year
• 28 plumes were identified in PSE’s Methane Risk Map, with a total of 1,249 to 5,788 people and one high school potentially at risk of unsafe benzene exposure
• The 96 plumes were observed emitting an estimated rate of more than 162,000 pounds of methane per hour
• The analysis shows that super-emitter methane release incidents, if not quickly mitigated, could result in substantial additional emissions beyond companies' publicly reported inventories

“For years, science has shown that the climate-warming and health-harming emissions from oil and gas operations are significantly higher than industry estimates,” said Alice Lu, MPH, Policy Analyst at Clean Air Council. “In addition to the importance of accurate emissions measurements and reporting, this report underscores the need for durable methane standards that safeguard Pennsylvania communities from emission events of all sizes. It’s critical that Pennsylvania adopts methane standards that achieve the strongest protections for its residents.”

The report demonstrates how satellites, other detection methods, and data can more accurately capture the extent of industry pollution, ground-truth company claims of responsible practices, and identify opportunities for real emissions reductions. It also includes recommendations to improve data accuracy and implement effective methane mitigation measures.

“Coupling existing tools with new tools and methods of measurement is a game-changer for better understanding the scale of the oil and gas methane pollution problem,” said Dakota Raynes, Senior Manager of Research, Policy, and Data from Earthworks. “The truth looks to be a lot closer to what independent scientists and advocates have been documenting for decades than the story the oil and gas industry itself has been telling.”