skip to main content

Aliso Canyon leak

In October 2015, SoCalGas discovered a leak at one of its injection and withdrawal wells at its Aliso Canyon natural gas storage facility, located in the northern part of the San Fernando Valley in Los Angeles County. The leak was sealed in February 2016, and the company has acknowledged the disruption it caused to nearby communities and the impact it had on the environment.

On October 23, 2015, SoCalGas detected a leak at one of the wells at its Aliso Canyon natural gas storage facility, located in the northern part of the San Fernando Valley in Los Angeles County. We regret any impacts that this unusual incident may have had on the environment, our customers and the communities we serve.

After discovering the leak, SoCalGas notified the appropriate regulatory, safety and health officials and attempted to plug the well by pumping fluids down the well shaft. SoCalGas also informed community members of the leak. In early December 2015, SoCalGas began drilling a separate relief well designed to facilitate plugging the leaking well at its base, approximately 1.5 miles underground. The leak was stopped on February 11, 2016.

To permanently seal the well and consistent with directives from the California Department of Conservation’s Division of Oil, Gas, and Geothermal Resources (DOGGR) and the CPUC, SoCalGas then injected cement into the well at its base, and on February 18, 2016, the DOGGR confirmed that the well was permanently sealed.

For details about related governmental investigations and orders, litigation, impact on system reliability, cost estimates, accounting and insurance, please see Sempra Energy’s Annual Report on Form 10-K and most recently filed Quarterly Report on Form 10-Q.

Greenhouse gas emissions

The Aliso Canyon leak resulted in the loss of natural gas equal to 2.1 million metric tons of CO2.  While this increases Sempra Energy’s annual emissions, it represents just one-half of one percent of the State of California’s annual carbon dioxide emissions. For context, transportation-related emissions in the state average 172.5 million metric tons of carbon dioxide equivalent (MMTCO2e) each year.

Even before the well was sealed, SoCalGas committed to mitigate the actual natural gas associated with the incident. Once the well was sealed, the utility began working with state officials to develop a framework to achieve this goal.

Efforts to address community concerns

Most of the residents living near the Aliso Canyon natural gas storage facility never left their homes. About 12 percent of the households within the five ZIP codes near the well chose to relocate under SoCalGas’ temporary housing program. As of June 15, 2016, less than 1 percent remained in temporary housing. SoCalGas is working to finalize the smooth transition home for these residents.

SoCalGas has installed more than 38,000 air filtration systems in approximately 11,000 homes, schools and businesses. As of June 15, 2016, SoCalGas’ dedicated community resource center had been open for more than 190 days and served more than 34,000 visitors.

SoCalGas cleaned public parks, private and community schools, and community playgrounds. Exterior cleaning has been completed at more than 1,650 houses.

As of June 15, 2016, the company had processed 46,000 expense reimbursement requests related to the leak, totaling nearly $87 million.

SoCalGas’ five commitments

 As part of its continuing effort to mitigate the impact of the leak, SoCalGas made five commitments to the community:

  1. Help Customers Return Home Safely: Help residents who relocated return to their normal lives as seamlessly as possible.
  2. Expand Community Resources: Continue to provide dedicated customer service to the impacted residents.
  3. Understand What Caused the Leak: Cooperate with regulatory agencies in their investigation into the cause of the leak.
  4. Assure Integrity of All Wells: Accelerate the inspection of other wells at Aliso Canyon and support regulatory policies that require adoption of best safety practices for all storage facilities.
  5. Address Environmental Emissions: Develop and implement a plan to mitigate the actual natural gas associated with the leak.

More details are at