Permian Basin Leaking 14 Times More Methane Than EPA Estimates: Study

Pipelines transporting natural gas in the Permian Basin oil field are leaking at least 14 times more methane than the Environmental Protection Agency previously estimated, according to a study published Tuesday.

Scientists at the Environmental Defense Fund (EDF), Stanford University, and the University of Arizona analyzed more than 10,000 miles of gathering pipelines--which transport unprocessed gas from wells to processing facilities--using aircraft with sensors equipped to detect plumes of methane.

Pipelines across the basin--which is located in western Texas and New Mexico and is the largest oil and gas field in the U.S.--are emitting at least 213,000 metric tons of methane per year, meaning 2.7 metric tons per year per kilometer of pipeline. That amount is 14 times greater than the EPA's national inventory has estimated.

"Applying this estimate to all gas gathering pipelines nationwide for illustrative purposes would increase the EPA inventory estimate for the entire natural gas system by 27%," wrote study co-authors Erin Murphy of the EDF and Jevan Yu of Stanford, in a blog post.

"We wouldn't accept these kinds of leaks from hazardous liquids lines and we shouldn't accept them from natural gas pipelines either."

The authors noted that about 50% of the emissions of methane--the potent greenhouse gas which has more than 80 times the heating potential of carbon dioxide in its first two decades in the atmosphere--come from just 15% of the pipelines' largest leaks.

"Finding and fixing a relatively small number of leaks could have significant climate benefits," wrote Murphy and Yu.

The methane emissions leaking from Permian Basin pipelines have a climate impact equal to 3.7 million passenger vehicles and represent enough natural gas to meet the energy needs of 2.1 million homes, noted the scientists, who said the research should push policymakers to strictly regulate gathering pipelines.

While a new rule issued in November 2021 by the Pipeline and Hazardous Materials Safety Administration (PHMSA) established safety standards for 90,000 miles of gathering lines--a major improvement over the 10,000 miles that had previously been regulated, said Murphy and Yu, "the overwhelming majority of gathering lines remain unregulated, which is inadequate to protect people and the environment."

The analysis was released days after researchers at the University of Michigan published a report showing that the practice of flaring, in which natural gas escaping from fossil fuel wells is burned, releases five times more methane than previously known.

A separate recent study from the University of Reims in France found that methane emissions in the Permian Basin were two to three times higher than companies reported to the EPA.

"It's somehow fitting that our largest oil and gas field shares its name with a major extinction event," said one observer of the latter study.

The United Nations said in a report last year that reducing methane emissions must play a larger role in the fight against the climate crisis. Methane emissions are currently projected to rise through at least 2040, but they could plummet by 45% by 2030 with a major effort to reduce leaks from infrastructure. That reduction could help stop the planet from heating by nearly 0.3degC by the 2040s, according to the United Nations.

"We wouldn't accept these kinds of leaks from hazardous liquids lines and we shouldn't accept them from natural gas pipelines either," said Bill Caram of the Pipeline Safety Trust, a watchdog organization.