For the greater part of a decade, residents near the Aliso Canyon underground gas storage facility – the site of the largest natural gas leak in U.S. history – have demanded its closure.
Those who lived near the Southern California Gas Co. facility during or since the catastrophic blowout, which took place between October 2015 and February 2016, have reported a host of health problems, from nosebleeds and rashes to dizziness and respiratory issues.
And they worry what other health impacts may stem from longterm exposure to potential emissions.
“Of course it needs to be shut down because the danger of the facility has never gone away and will never go away,” said Issam Najm, an environmental engineer who’s lived in the neighboring Porter Ranch community for more than two decades.
SoCalGas, which implemented enhanced safety measures after the 2015 blowout, has pushed back on claims that the facility is unsafe.
Beyond that, efforts to shutter the natural gas storage facility in the Santa Susana Mountains have been complicated by the desire to balance those demands with the needs of Californians who expect a reliable source of energy while keeping their utility bills stable.
Over the past decade, in response to the blowout, state regulators set different limits on how much natural gas could be stored at Aliso Canyon.
The facility has capacity to store up to 86 billion cubic feet (Bcf) of natural gas, though SoCalGas is currently only approved to store up to 68.6 Bcf. There was a period when the company was approved for even less – as low as 15 Bcf during the blowout – though representatives for SoCalGas later convinced the California Public Utilities Commission that the storage capacity needed to increase to achieve energy reliability during winter.
This month, as part of its biennial assessment of Aliso Canyon, CPUC staff recommended lowering the maximum amount of natural gas the facility can store to 58.6 Bcf, a reduction of 10 Bcf.
At the same time, the staff noted the CPUC board may wish to lower the cap by a smaller amount in light of forecasts that gas commodity prices could go up during the 2026-27 winter season.
“While we will comment further through the regulatory process, the reality is that natural gas storage at Aliso Canyon is safe and, at current inventory levels, protects California families from utility bill price spikes and provides the electric grid with reliable energy,” a spokesperson for SoCalGas wrote in an email about the CPUC staff’s latest recommendation.
Unprecedented blowout
The gas leak that began on Oct. 23, 2015 lasted nearly four months. Over the course of that period, some 109,000 metric tons of methane escaped into the air before SoCalGas fixed the leak on one of its wells.
Ten years in, some nearby residents say they continue to suffer physical ailments or worry about future health complications stemming from exposure to Aliso Canyon gas emissions.
For them, the recent publication of a study by UCLA researchers linking an increase in low birth weights among newborns whose mothers lived near Aliso Canyon during the final trimester of their pregnancy was proof that a gas storage facility has no place operating in such close proximity to thousands of homes in the San Fernando Valley.
Representatives for SoCalGas, meanwhile, have said independent regulatory agencies, including the California Office of Environmental Health Hazard Assessment, California Air Resources Board and the South Coast Air Quality Management District, previously reviewed data and “concluded that the Aliso Canyon gas leak did not pose longterm health risks to the public.”
Since 2015, the utility company has reported implementing enhanced safety measures. These include replacing the inner steel tubing of each approved well and using the casing around the tubing to provide a secondary, physical barrier to guard against future leaks; withdrawing and injecting natural gas only through the inner steel tubing of wells that have passed all tests and been approved by the California Geologic Energy Management Division for use; and operating the facility at reduced pressure.
Even so, some nearby residents and environmentalists say the facility should have fully shut down long ago – or at least be far on its way toward a complete shutdown at this point.
They noted the state’s ongoing effort to transition Californians away from fossil fuels in favor of renewable energy. Those who want Aliso Canyon shut down say that with each passing year there will be less need for a natural gas storage facility.
Debate over facility’s need
Regardless of any effort to move away from using natural gas, state regulators do not believe now’s the time to completely shut down the Aliso Canyon site.
Last December, the CPUC board voted to keep the facility in operation for energy reliability reasons and to keep energy costs down for consumers.
At the same time, the board adopted a framework for when it would start to consider shutting down the facility. Those talks would occur two years out from when the peak day demand forecast for natural gas is projected to drop to 4,121 million metric cubic feet per day – something that’s not expected to occur until after 2030. (Last year’s peak day demand was forecasted at 4,618 million metric cubic feet per day.)
Critics of the CPUC’s plan said the framework left open-ended the exact timing of a shutdown.
A spokesperson for SoCalGas, meanwhile, emphasized the role natural gas plays in meeting consumer demands. Last year, the California Energy Commission reported that 40% of California’s in-state electric generation came from natural gas, and data from the California Independent System Operator showed that natural gas supported 45.2% of its 2024 system peak, she said.
“Natural gas storage is especially important for reliable electric generation because it supports renewable power sources, like wind and solar, to help keep the lights on,” SoCalGas said in a statement. “When the wind doesn’t blow or the sun doesn’t shine for renewable electric generators, the natural gas from Aliso Canyon helps to fill those energy gaps.”
In addition, the company said natural gas provides two-thirds of the energy used in homes in California but usually accounts for just a quarter of the average household energy bill.
“Aliso Canyon is expected to remain one of the state’s most important energy assets, supporting reliable and affordable energy access for millions of California consumers into the foreseeable future,” the company said.
Aliso Canyon is the largest of SoCalGas’ storage fields, serving more than 11 million customers and fueling 17 power plants.
To keep gas prices affordable while ensuring a reliable supply of energy for the region, SoCalGas purchases natural gas when market prices are low, stores it in underground wells, then draws from this stock at times when customer demand for natural gas is greater than the supply flowing into the area through pipelines. This occurs on cold winter days when customers heat their homes or during summer months when more people use air conditioners, for example.
Despite the role the Aliso Canyon facility plays in meeting Californians’ energy needs, the state’s last two governors previously expressed interest in seeing the facility closed.
In 2017, then-Gov. Jerry Brown directed the CPUC to draft a plan to shut down the facility by 2027. Two years later, in 2019, Newsom directed the CPUC to expedite that closure.
Pressure on Newsom
But critics say Newsom has been largely silent on the issue since and accused him of flip-flopping on his position.
“Newsom still has time left in his term to remedy this. … If Gov. Newsom wants to present himself as a climate leader, then he actually needs to demonstrate climate leadership,” said Andrea Vega, an organizer with Food & Water Watch, an environmental advocacy group which last year ran a digital ad campaign in a handful of states accusing Newsom of walking back his directive.
Last month, during Newsom’s appearance at New York Climate Week, the group led an effort in delivering a letter, signed by 40-plus organizations, to the governor, urging him “to live up to (his) climate and consumer protection rhetoric.”
Daniel Villaseñor, a spokesperson for Newsom, dismissed claims that the governor has flip-flopped, saying Newsom remains committed to shutting down the Aliso Canyon facility “in a way that maintains safe, affordable, and reliable energy and protects public health and safety.”
“It would be irresponsible to close Aliso Canyon before demand for natural gas declines and the facility is no longer needed,” Villaseñor said in a statement. “Closing the facility before residents substantially reduce their natural gas consumption is a recipe for precisely the kind of price spikes we’ve seen in the gasoline market — supply shortages we’ve worked to address with sufficient inventories.”
Activists who want the facility shuttered, meanwhile, have vowed not to go away until their demands are met.
“It’s a battle that Food & Water Watch is not going to give up anytime soon,” Vega said. “We are still continuing to work with local community groups on ensuring that No. 1, the facility is shut down as quickly as possible, and No. 2, for there to be actual clean energy resources coming into the (San Fernando) Valley.”
Given the framework the CPUC board approved last year, Najm, the longtime Porter Ranch resident, doesn’t expect to see a complete shutdown for at least a decade.
“I’m a realist. I understand that multiple entities have to be OK with this, and certainly there’s a lot of opposition (to shutting it down),” he said. “I would’ve been happy with a gradual plan that was set in place to go ahead and do ‘X’ reduction every year … because at least there would’ve been a roadmap in place.”
Instead, he said, “what we ended up with is a lot of uncertainty.”