LOS ANGELES — The biggest gas storage facility in the West resumed operations Monday, nearly two years after a blowout led to the nation’s largest-known methane release and drove thousands of families from their Los Angeles homes.

Southern California Gas. Co. said it began injecting gas in underground wells after it completed final steps required to resume limited operations and shortly after a state appeals courts rejected attempts to the block the restart of the Aliso Canyon facility.

State regulators gave approval last week to pump a limited amount of gas into underground storage wells after an overhaul, rigorous testing and the application of stricter rules put in place since the massive leak.

The site has been largely out of commission since an October 2015 well blowout spewed climate-changing methane for nearly four months, sickened residents and drove 8,000 families from their homes.

Los Angeles County unsuccessfully tried to keep the facility closed until it showed it could safely withstand an earthquake. A judge ruled he didn’t have authority to override an order from the California Public Utilities Commission. Appeals court judges shot down efforts to halt the restart.

The state said the facility is safe and earthquake fears are overblown.

SoCalGas said it has met and sometimes exceeded the state’s safety requirements at the storage field, and it needed to increase its inventory at the facility to avoid an energy shortage.

The utility and state regulators have said Aliso Canyon is necessary to provide home heating in winter and to fuel gas-fired power plants during times of peak demand, such as during summer heat waves.

However, predictions of blackouts over the past year while the facility was closed have not come to pass. That has led to calls from many residents in Porter Ranch and other San Fernando Valley suburbs — some who are still reporting health symptoms — to permanently shut it down.

State Sen. Henry Stern, D-Los Angeles, said “blackout saber-rattling is kind of blackmail” to scare people. He and others who want to see more evidence that Aliso Canyon is necessary and safe before reopening were regrouping to plot their next steps.

“It’s a tough day,” Stern said. “There’s a bit of a faith-based strategy. We’ve all got to cross our fingers and hope nothing bad happens.”