Methane is a greenhouse gas even more potent than carbon dioxide, and some 1,000 tons of it has been leaking into the air each day at the Southern California Gas Company's (SoCal Gas) Aliso Canyon storage field since October 23. So far, more than 80 thousand tons of methane has poured into the atmosphere, which has forced evacuations of nearby neighborhoods, and could have long-term impacts far beyond the hills above Los Angeles.
Around 1,700 homes and two schools were evacuated because of the leak, as noxious odors settled over Porter Ranch, about 20 miles from downtown Los Angeles. California officials have helped the company in a series of efforts to stop the leak, but it could be weeks or months before the gas flow is halted.
The underground storage facility — the largest of its kind on the West Coast — contains billions of cubic feet of natural gas, stored under pressure to supply SoCal Gas's 20 million customers.
The exact cause of the leak remains a mystery, but company officials say the problem began when an underground well casing failed, allowing the pressurized gas to push through geological cracks to the surface near Porter Ranch.
A UC Davis scientist flying in a pollution-detecting airplane provided the first estimates of methane emissions spewing from the storage facility. Those estimates were provided to the California Air Resources Board in November.
“To put this into perspective, the leak effectively doubles the emission rate for the entire Los Angeles Basin,” Pilot and UC Davis project scientist Stephen Conley said in a statement. “On a global scale, this is big.”
To put "big" into perspective, the Environmental Defense Fund (EDF) is calling it a "mega-leak," while environmental law activist Erin Brockovich told CNN: "It's the BP spill on land." Brockovich, who lives in Agoura Hills, roughly 20 miles away from the site of the spill, has taken up the cause of local residents' concerns.
Since the leak was first noticed by SoCal Gas workers, repeated attempts to fix the leak have been unsuccessful, which has left gas billowing downhill into Porter Ranch.
Gov. Brown Declares State of Emergency
With no end in sight, California Governor Jerry Brown on Wednesday declared a state of emergency in response to the leak, which also directs further action by SoCal Gas to protect public health and safety, ensure accountability and strengthen oversight of gas storage facilities.
The proclamation calls for the the gas company to maximize the amount of natural gas being removed from the facility, capture leaks while relief wells are being built, and to identify how the company will stop the leak if relief wells don't seal the problem, or if the existing leak gets worse. The California Public Utilities Commission also will make sure SoCal Gas covers costs related to both the leak and its response, while protecting the company's own ratepayers.
“SoCal Gas recognized the impact this incident is having on the environment,” SoCal Gas President Dennis V. Arriola said in a letter last week to Gov. Brown. In response, the company has drilled a relief well while also pouring a brine solution and other materials into the damaged well in an attempt to seal it, so far without noticeable results.
The company’s losses in natural gas alone are estimated in the tens of millions of dollars, with total damages likely to exceed that figure several times over. Many neighbors already have filed lawsuits, which has come as part of a growing outcry that includes calls for the company to close the facility altogether.
Policy Action to Cut Methane Leaks
The Aliso Canyon leak is a prominent example of the risks associated with methane emissions from oil and gas operations, which scientists and environmental groups have long sought to call attention to.
In August 2015, the U.S. Environmental Protection Agency, under the direction of President Obama, proposed the first-ever rule to directly limit methane emissions from oil and gas operations, unlocking a new opportunity to reduce climate pollution. Leading investors representing $1.5 trillion in assets under management released a statement of support for a strong federal standard to reduce methane emissions from the oil and gas industry.
Often, even substantial leaks can sometimes go completely undetected, Adam Brandt, an assistant professor at Stanford University’s Institute for the Environment, told The Washington Post. Even large leaks can be hard to find if they occur away from populated areas, and one important step forward for sustainability will be to design ways to quickly detect and fix these large leaks soon after they happen.
For the past several years, EDF has been collaborating with seven oil and natural gas companies on its Methane Detectors Challenge, aimed at identifying next-generation technologies that will help better monitor and reduce methane emissions from oil and natural gas operations. And companies such as Newlight Technologies have developed processes that turn methane into AirCarbon, a plastic that has been used to make products such as iPhone cases — but it is unlikely such efforts could do much to mitigate the damage caused by a leak of this size.