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The largest natural gas leak ever recorded is jeopardizing health and causing evacuations for thousands of Southern California residents. And two months into it, scientists and engineers still can’t figure out a way to contain the seeping gas.
It is easily the worst environmental disaster since BP’s Deepwater Horizon oil spill in 2010...
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spewing natural gas into the atmosphere at up to 110,000 pounds per hour...
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Methane is estimated to be leaking out of the Aliso Canyon site at a rate of about 62 million standard cubic feet, per day. That’s the same short-term greenhouse gas impact as the emissions from 7 million cars.
While the well still needs to be permanently sealed with cement and inspected by state regulators, the announcement by Southern California Gas Co. marked the first time the massive leak has been under control since it was reported Oct. 23. "We've achieved control of the well today," said Jimmie Cho, a SoCalGas senior vice president. He said he was very confident they would complete the job. The leak is expected to cost the company, a division of Sempra Energy, $250 million to $300 million, according to a filing with the Securities and Exchange Commission.
This Dec. 17, 2015 file photo provided by Earthworks shows an overhead aerial view of the relief well at the Aliso Canyon facility above the Porter Ranch area of Los Angeles. The utility says it has stopped the natural gas leak near Los Angeles after nearly 4 months
That figure could climb much higher because it only accounts for costs of capping the well, lost gas and relocating families. It does not include potential damages from more than 65 lawsuits, penalties from government agencies and expenses to mitigate pollution, which the company noted could be significant. If the plug holds and all goes according to plan to seal the well, the upscale Porter Ranch community in the San Fernando Valley could begin to return to normalcy after schools were closed and 6,400 families were uprooted as they complained of headaches, nausea, nosebleeds and other symptoms as an intermittent stench wafted through the area. Public health officials blamed their woes on an odorant added to gas so it can be detected and have said they don't expect long-term health impacts.
Vicky Walker, who lives close to the facility, said the smell was particularly strong the past few nights but wasn't noticeable Thursday afternoon. She spent three to four nights a week in a hotel after developing a cough, but returned regularly to work from her home office. But she gained five pounds as she stayed inside as much as possible and stopped walking her dog. "I want to get back to life as I knew it as soon as possible," Walker said. "And I hope property values don't suffer." The leak at the largest underground gas storage reservoir in the West was declared an emergency by the governor. At its peak, the leak was estimated to contribute about a quarter of the state's climate-altering methane emissions, leading some to call it the worst environmental disaster since the 2010 BP oil spill in the Gulf of Mexico.
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At its peak, 60 tons per hour of natural gas was spewing from a ruptured underground pipeline at the Aliso Canyon storage field, effectively doubling the methane emissions of the entire Los Angeles metropolitan area, the researchers said. The stench of fumes from the site 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. From the time it was first detected on Oct. 23 until it was largely plugged earlier this month, the leak discharged a total of 97,100 tons — or 5 billion cubic feet (142 million cubic meters) — of methane to the atmosphere, according to the study, published in the journal Science.
Map of Porter Ranch in Los Angeles area, where a gas leak has been sickening some residents and causing the large-scale release of methane.
The chief component of natural gas and a far more potent greenhouse agent than carbon dioxide, methane persists in the atmosphere for 10 years. The total release from Aliso Canyon is equivalent to the annual energy-sector methane emissions of a medium-sized European Union country, the study said. "Our finding means that the Aliso Canyon leak was the largest accidental release of methane in the history of the U.S.," Tom Ryerson, a scientist for the National Oceanic and Atmospheric Administration (NOAA), and co-lead of the study, said in a NOAA statement about the research.
Comparisons
The 2004 collapse of an underground gas storage facility in Texas actually expelled more natural gas, but it was mostly consumed in an explosion and fire, so the methane never reached the atmosphere, the study said. "Aliso Canyon will have by far the largest climate impact" and will "substantially impact the state of California greenhouse gas emission targets for the year," the study said.
Porter Ranch is near the entrance of Southern California Gas Company's Aliso Canyon storage facility.
In terms of its heat-trapping greenhouse potential, the volume of leaked methane was equivalent to putting 572,000 passenger cars on the road for a year, according to the scientists. The Aliso Canyon facility, owned by Southern California Gas, a division of San Diego-based Sempra Energy, is the fourth largest gas storage field of its kind in the United States. The volume of methane that escaped represents just 3 percent of its total storage capacity, the study said.
California Methane Leak Biggest Ever in US, Scientists Say
