Plumes of the super-warming greenhouse gas methane were spotted over the Midwest last month. U.S. pipeline giant Energy Transfer said the releases were triggered by “routine work” on its natural-gas infrastructure.
The emissions were likely limited in scope. By one estimate if they lasted an hour they would have roughly the same short-term climate impact as the annual emissions of about 700 cars. A spokesperson for Energy Transfer, which also owns the contentious Mariner East pipeline in Pennsylvania, had no information on the amount released.
However, the releases raise questions about the urgency and ability of operators to respond to the climate crisis, and whether these emissions can be avoided. “During this time routine work was being performed,” the spokesperson said in an email. “All appropriate notifications were made.”
Many global oil and gas operators have said they are committed to reducing the methane intensity of their operations by cutting back on intentional emissions of the greenhouse gas. The industry is under pressure to improve operations to tackle climate change and respond to increasing investor scrutiny on environmental issues. Still, multiple operators continue to justify releases as a part of normal operations.
Halting intentional releases and accidental leaks of methane, the primary component of natural gas, could do more to slow climate change than almost any other single measure. Methane has more than 80 times the warming impact of carbon dioxide over the short term.
Scientists are targeting methane emissions from the oil and gas industry because they offer the biggest potential cuts at the cheapest cost. The U.S. was the world’s second-largest methane emitter last year after Russia, according to an estimate from the International Energy Agency.
The Aug. 9 releases were tied to work taking place on Energy Transfer’s Panhandle Eastern natural gas pipeline that extended to Aug. 27, according to an official notice. Excavations on the pipeline, which runs from Oklahoma to Michigan, appear to precede pipe replacement that started on Aug. 24 and is slated to be done on Sept. 13, the notice said.
One possible reason for the releases is what is known in the industry as “blowdowns,” where companies can legally dump methane into the atmosphere for maintenance, shutdown, start-ups and for emergencies, said Sharon Wilson, senior field advocate for the nonprofit Earthworks.
The U.S. Environmental Protection Agency has a recommended practice for clearing gas out of pipe segments, that the “industry doesn’t typically follow,” she said. Specific mitigation approaches can curb emissions from blowdowns by up to 90%, according to a 2016 report from consultancy M.J. Bradley & Associates.
Bloomberg News reported on a plume of methane spotted over Alberta in April that coincided with a scheduled blowdown of a pipeline operated by a unit of TC Energy Corp. The operator declined at the time to say how much methane it emitted and said it reports data on emissions to regulators and in public forums.
Similarly, when asked about the concentration of the gas near their assets, global operators including Gazprom in Russia told Bloomberg News that the releases were necessary for safe operations and met all regulatory and legal requirements.
Energy Transfer, which is controlled by billionaire Kelcy Warren, declined to comment on a third release detected on Aug. 11 over central Kansas, and which was near other energy infrastructure owned and operated by multiple companies, including active and abandoned oil and gas wells.
All three methane plumes were detected and analyzed by the Paris-based geoanalytics firm Kayrros SAS, which used data from the European Space Agency’s Sentinel-5P satellite.
In August 2020, the EPA opened an investigation after Bloomberg News reported on a methane release over Florida to determine if the Clean Air Act was violated.
Preliminary findings indicate the release may have occurred from work at a natural gas compressor station, the agency said at the time. The timeline coincided with the emergency shutdown of a gas compressor that’s part of the Florida Gas Transmission Pipeline, a joint venture between Energy Transfer and Kinder Morgan Inc.
Satellite detection of methane plumes from natural gas supply chains has revealed a greater climate impact than previously thought from the fossil fuel long promoted by producers as a bridge to renewables. Multiple studies show that methane emissions from oil and gas infrastructure are often higher than what operators and governments report.
“It’s important to note that satellite monitoring does not stop methane any more than a mammogram stops breast cancer, but they are both valuable to let us know there is a problem,” said Wilson of Earthworks. “We already know we have a methane problem from oil and gas that needs to stop before it becomes terminal.”
Energy Transfer’s former Sunoco Pipeline unit is building the Mariner East pipeline system to delivers such natural gas liquids as propane from Western Pennsylvania to an export terminal in Marcus Hook, Delaware County.
The $5.1 billion project transports gas liquids and liquid fuels, such as gasoline, but not gaseous materials like methane. It is a key link in the state’s effort to promote Pennsylvania shale-gas development.
But its construction has provoked sharp opposition from residents and aroused fears about pipelines transporting highly volatile liquid fuel near residences, schools, and nursing homes.
Pennsylvania has assessed about $16 million in penalties against the Mariner East project for construction mishaps. The project, which initially had a completion date of 2019, now is expected to be finished this year.
The project has been delayed in part because of legal challenges of its construction permits and its public utility status and because of complications that have arisen as Sunoco threaded the pipelines through densely populated Delaware and Chester Counties.
In July, Energy Transfer LP agreed to pay a $1 million fine to settle safety violations over a fiery 2018 natural gas pipeline explosion that destroyed a home in Western Pennsylvania.
Read More: Energy Transfer admits it’s the cause of methane plumes in midwest