After 16 Weeks, The Massive Methane Leak In California Is Finally Plugged

CREDIT: Dean Musgrove/Los Angeles Daily News via AP, Pool, File

The 16-week-long gas leak at California’s Aliso Canyon Storage Facility, located about 30 miles northwest of downtown Los Angeles, has been temporarily stopped, an important first step towards permanently capping what has become the largest single release of methane into the atmosphere ever recorded. The leak has been called the largest environmental disaster since the 2010 BP oil spill, and thousands of families have been forced to evacuate their homes due to public health concerns.

“We have temporarily controlled the natural gas flow from the leaking well and begun the process of sealing the well and permanently stopping the leak,” Jimmie Cho, senior vice president of gas operations and system integrity at Southern California Gas Co. (SoCalGas), the utility that manages the storage facility, said in a statement released Thursday.

The process to begin stopping the leak began in early December, when the utility began drilling a relief well. On Thursday, workers successfully intercepted the base of the leaking well, and began diverting “heavy fluids to temporarily control the flow of gas out of the leaking well,” according to the SoCalGas release.

The relief is only temporary, however, and the utility notes that permanently stopping the leak could take several days, as cement needs to be pumping into the leaking well to seal it indefinitely.

Once the well is sealed, displaced residents will have eight days to relocate back to their homes. Rep. Brad Sherman (D-Porter Ranch), however, said on Wednesday that he wants to delay the eight-day time limit until tests show that the air surrounding the storage facility and the adjacent community of Porter Ranch is free of natural gas.

More than 6,000 families have been forced from their homes by the leak. Natural gas contains odorants, added to help detect leaks, which can cause health issues like nausea, dizziness, and nosebleeds. There is also some concern that the leak might have released oil-related toxins such as benzene, potentially left over from the well’s history as an oil-storage facility.

“Most of the families in the community are very excited to get back, but they will not be distracted by the leak stoppage. They still want to know that their homes are safe,” Paula Cracium, president of the Porter Ranch Neighborhood Council, told the Los Angeles Times.

In addition to potential health issues, the Aliso Canyon leak has been a huge climate disaster for California. Methane is a potent greenhouse gas 84 times more efficient at trapping heat, in the short term, than carbon dioxide. At one point during the 16 weeks that the well was emitting methane, the leak accounted for one-quarter of California’s total greenhouse gas emissions. According to the Environmental Defense Fund, roughly 96,000 metric tons of methane leaked from the well between October 23 and February 11, which is the short-term greenhouse gas equivalent of roughly half a million cars driving for an entire year.

SoCalGas has estimated that the leak could cost at least $250 million to $300 million. In addition to clean-up and relocation costs, SoCalGas faces dozens of lawsuits from residents, businesses, and regulators. L.A. County also recently filed criminal charges against the company for failing to immediately notify state authorities about the leak.