For more than 100 days in 2015 and 2016, gas leaked out of the Aliso Canyon Natural Gas Storage Facility near Los Angeles — the largest known leak of methane in United States history. More than 8,300 households evacuated, and people exposed to the gas reported nosebleeds, dizziness and respiratory problems.
This week, California regulators said they now knew why the environmental catastrophe happened.
In a 258-page report, investigators said that groundwater had corroded the metal lining of a more-than-50-year-old underground well, leading to its rupture at 892 feet below ground. The report also said that SoCalGas, the company that owns and operates the natural gas well, did not meaningfully investigate or analyze more than 60 previous leaks at the facility. The company did not properly monitor its wells at the site, the report said, adding that “the approach to well integrity at Aliso Canyon had been reactive rather than proactive.”
In a statement on Friday, SoCalGas said the report “marks an important milestone in helping the region and California move forward from the Aliso Canyon natural gas leak.” The company said that it had addressed “most, if not all” of the causes of the leak identified in the investigation, which was conducted by a private company, Blade Energy Partners, at the request of California regulators.
“In Blade’s opinion, there were measures, though not required by the gas storage regulations at the time, that could have been taken to aid in the early identification of corrosion and that, in their opinion, would have prevented or mitigated the leak,” SoCalGas said in its statement. “We