An underground natural gas pipeline rupture that caused the largest-ever methane leak in California has been permanently capped, paving the way for thousands of displaced Los Angeles residents to return home, state regulators said on Thursday.
Officials confirmed on Wednesday night that the subterranean pipeline breach at the Aliso Canyon gas storage field owned by the Southern California Gas Co. was successfully sealed after a series of independent laboratory tests, Jason Marshall, the chief deputy director of the California Department of Conservation, told reporters.
The utility, a division of San Diego–based Sempra Energy, said Friday that infrared monitoring by state regulators showed that a newly drilled relief well managed to finally intercept and halt the gas flow but that more work needed to be done before the leak could be permanently capped.
A series of follow-up emissions and infrastructure tests confirmed that the cement plug pumped into the crippled injection well pipe was holding, Marshall said.
The stench of gas fumes spewing from the site has sickened scores of people and prompted the temporary relocation of more than 6,600 households from the northern Los Angeles community of Porter Ranch at the edge of the gas field.
Marshall said those displaced residents were all expected to return to their homes by next Thursday.