​​​​​​​​Aliso Canyon Storage Facility

​​​​​On July 19, 2017,  the California Public Utilities Commission (CPUC) and Department of Conservation, Geologic Energy Management Division (CalGEM)​ announced that the Aliso Canyon natural gas storage facility in Los Angeles County could reopen at greatly reduced capacity.

This decision followed months of rigorous inspections, testing and engineering analyses, and the implementation of new safety protocols at the facility operated by Southern California Gas Company (SoCalGas). The robust oversight is to ensure the protection of the public and environment following a major methane gas leak that began in October 2015 and was halted after four months.

In consultation with nationally recognized experts from the Lawrence Livermore, Lawrence Berkeley, and Sandia National Laboratories, CalGEM completed a comprehensive safety review of the 114 wells at the facility. Each well was required to either pass a battery of tests to potentially be eligible to resume gas injection or be taken out of operation and isolated from the reservoir (test results). Wells that were isolated from the reservoir were ultimately required to be plugged and abandoned−that is, filled with cement and permanently sealed.

As of March 8, 2019, 65 injection wells have passed all required tests and are back in service. Forty-one wells are permanently isolated from the gas storage reservoir, their wellbores filled with a combination of fluid and cement. Another three wells are isolated, awaiting further tests to determine whether they will be returned to service or plugged and abandoned. Four wells are plugged and abandoned. The well that was the source of the methane leak was taken out of operation.

Per the CPUC, withdrawals of natural gas from Aliso Canyon wells that have passed the required CalGEM tests are allowed when demand exceeds the supply available using the non-Aliso storage fields. These withdrawals must be in compliance with the Aliso Canyon Withdraw Protocol.  Pursuant to Senate Bill 380, the CPUC also has an active proceeding I.17-02-002 to determine the feasibility of minimizing or eliminating use of the Aliso Canyon facility while maintaining energy and electric reliability for the region.

CalGEM and the CPUC are conducting parallel root-cause analyses of the well failure at Aliso Canyon. Those will follow an independent root-cause analysis by Blade Energy Partners that CalGEM and the CPUC directed SoCalGas to conduct (see below for those findings).  

Additionally, per an agreed-upon work plan​, CalGEM required SoCalGas to ​conduct studies on seismic risk using approved third-party consultants. CalGEM​ will review the findings with recognized experts from the National Laboratories to determine whether they meet requirements.

CPUC:​ Aliso Canyon Well Failure Root-Cause Analysis (May 17, 2019)


Aliso Canyon Storage Facility Document Repository