The four-month leak at the Aliso Canyon natural gas storage facility near Porter Ranch emitted 109,000 metric tons of methane into the atmosphere, according to a final estimate released Friday by the California Air Resources Board.
The figure is roughly on par with earlier estimates of the leak, which began in October 2015 and was capped in mid-February and has been called the largest of its type in U.S. history.
“This was the largest methane leak in the history of the state and CARB is determined to ensure that the environmental damage caused by this potent greenhouse gas is fully addressed and mitigated by the Southern California Gas Co.,” said CARB chair Mary D. Nichols.
SoCalGas officials said the company committed nearly a year ago to mitigate the emissions and work with the state to develop efforts to do so.
“We continue to stand by our commitment to mitigate the actual emissions from the leak and are working diligently on a mitigation plan,” company spokesman Chris Gilbride said. “We have signed letters of intent with several California dairies to manage methane emissions and will finalize our mitigation plan in the coming months.
We have just received the revised estimated emissions numbers released by the ARB today, and we are reviewing them at this time,” he said.
According to CARB, the leak was responsible for about 20 percent of the total statewide methane emissions during those four months, and equaled roughly half of the emissions from the state’s industrial dairies, which are the largest source of methane emissions in the state.
— City News Service