There was “a small natural gas leak” last week at the Aliso Canyon storage facility above Porter Ranch but it was “quickly isolated and stopped.”
The gas leak, which was discovered by Southern California Gas Co. officials at 4:50 p.m. last Monday, was in an above-ground pipe used to withdraw natural gas from the reservoir, Gas Co. officials said in an email notification to interested parties sent at about 9:30 p.m.
“Our initial findings indicate the leak began only a short period of time before its discovery and that the release of natural gas was small,” the notification said.
Monday’s gas leak was at least the fourth at the Aliso Canyon field since Oct. 23 — when a natural gas storage well operated by the Gas Co. began spewing an estimated 100,000 metric tons of methane in the worst natural gas leak in U.S. history. The nearly four-month leak that displaced some 8,000 area families and sickened others was apparently caused by damage to the well casing several hundred feet underground though state officials have not yet released the results of their investigation.
A second minor oil and gas leak caused by a failed rubber seal on a device in April caused about 84 gallons of oil mixed with water and gas to spill from a well at the Aliso Canyon field. Another natural gas leak in a pipeline near a well ended up found and fixed in July shortly after it was discovered.
The cause of the latest leak had yet to be determined. Gas Co. officials said they did not expect area residents to notice the gas.
“At no point was there a threat to public safety,” the notification said.
The Gas Co. has notified relevant agencies and “is in the process of making permanent repairs,” officials said.