The Aliso Canyon Natural Gas Storage Facility (Aliso Canyon), located in the Santa Susana Mountains of Los Angeles County, is the largest natural gas storage facility in California. Southern California Gas Company (SoCalGas) crews discovered a leak at the natural gas storage well at Aliso Canyon on October 23, 2015. After several attempts, SoCalGas stopped the leak on February 12, 2016, sealing the well on February 15, 2016. It was later plugged and abandoned. More information on the well kill attempts can be found on the background on Aliso Canyon and actions to date.

On July 19, 2017, after inspection and analyses of all the wells at Aliso Canyon, we decided along with the California Geologic Energy Management Division (CalGEM, formerly known as the Department of Conservation’s Division of Oil, Gas, and Geothermal Resources, or DOGGR), that the facility was safe to operate. It was reopened at a reduced capacity. CalGEM, which has primary jurisdiction over Aliso Canyon’s underground facilities, decided the maximum allowable operating pressure in the field to be 2,926 psi, which translates to an inventory of 68.6 billion cubic feet (Bcf) of natural gas. This is a 17.4 Bcf reduction compared to Aliso Canyon’s pre-leak capacity of 86 Bcf. Read more information on CalGEM’s Aliso Canyon Storage Facility page.

Following the direction provided by the legislature in California Public Utilities Code Section 715, the CPUC determines the inventory needed "to ensure safety and reliability for the region and just and reasonable rates in California.” We have revised this inventory level several times in response to changing conditions and have continued to do so through Commission decisions since Section 715 expired on January 1, 2021. Most recently, we set the Aliso Canyon inventory at 68.6 Bcf on August 31, 2023, in order to reduce the likelihood of high gas and electricity prices. The inventory level will be revisited in Phase 3 of the Aliso Canyon investigation described below.

We continue to coordinate with the California Energy Commission (CEC), the California Independent System Operator (CAISO), the Los Angeles Department of Water and Power (LADWP), and CalGEM to monitor natural gas reliability and affordability in Southern California and protect public safety. Since 2016, we have developed Summer and Winter Reliability Assessments that assess energy reliability challenges in Southern California in the coming season. We also periodically create Southern California Conditions and Operations Reports (Look Backs) that look back on various seasonal reliability events.

On our investigation webpage you can find information on the proceeding we opened on Feb. 9, 2017 (called an Order Instituting Investigation; I.17-02-002) to determine the feasibility of minimizing or eliminating the use of Aliso Canyon.

Find information about our actions and links to information available on other state agency websites, starting with the latest information.

Aliso Withdrawals

CPUC Reports

Useful Links & Documents

For more information, please contact

External Affairs Division
California Public Utilities Commission
505 Van Ness Avenue
San Francisco, CA 94102

(415) 703-1366