More wells passed safety inspections at the Aliso Canyon natural gas storage facility in Los Angeles, Southern California Gas Co. said on Sept. 19, but the company has more work to do before it can inject gas into the giant field the utility shut last fall due to a massive methane leak that was not plugged until February.

Under state law, SoCalGas cannot inject gas into Aliso Canyon until the California Division of Oil, Gas and Geothermal Resources (DOGGR) approves the company's testing of the 114 wells at the facility to ensure their safety.

Several local groups want the storage field permanently shut, as do many residents who had to evacuate their homes due to the leak.

SoCalGas is owned by California energy company Sempra Energy and Aliso Canyon is the biggest of its four storage fields. It supplies natural gas to homes and businesses in Southern California, including power plants and refineries.

According to its latest report on Sept. 16, SoCalGas said 23 wells passed all safety tests, 15 awaited test results and 76 were temporarily out of operation.

All wells must either pass all tests or be taken out of service before DOGGR can call a public meeting. Since DOGGR must give the public 15 days notice before a meeting, SoCalGas could not start injecting gas into Aliso Canyon until some time in October at the earliest.

SoCalGas spokesman Chris Gilbride could not speculate on when the company may complete tests and return the storage facility to service. He said the company has completed all tests on 25 wells and 23 have received final DOGGR approval.

In addition to DOGGR, the California Public Utilities Commission (PUC) must also determine that the field is safe to operate. The PUC has directed SoCalGas to maintain a minimum withdrawal capacity at Aliso Canyon to minimize the risk of gas shortages that could result in electricity outages.

Once enough wells have passed all tests and received DOGGR approval to meet the PUC's withdrawal requirements, Gilbride said SoCalGas will temporarily plug the remaining wells and take them out of service.

Once those wells have been plugged and isolated from the reservoir, SoCalGas can request authority to resume injections, he said.

At that point, DOGGR and the PUC would be able to undertake their review and certification process, which will include a public hearing, as provided by Senate Bill 380, prior to SoCalGas resuming injections, he said.