By CBSLA Staff

LOS ANGELES (CBSLA) – A state commission voted Thursday to expand capacity at the Aliso Canyon underground natural gas storage facility, which in 2015 was the source of the largest methane gas leak in U.S. history, forcing thousands of Porter Ranch residents to flee their homes.

FILE — The SS-25 well, where a 2015 gas leak occurred, stands at the SoCalGas Aliso Canyon underground natural gas storage facility in Porter Ranch on Jan. 12, 2017. (Getty Images)

The proposal, passed unanimously by the California Public Utilities Commission expands the storage at the Southern California Gas Company-owned facility to 60% capacity, or 41.6 billion cubic feet.

Indicated Shippers, a group of oil companies, including California Resources Corporation, Chevron, Phillips 66 and Tesoro, made the requests to increase storage limits at Aliso Canyon.

Beginning in October 2015, the Aliso Canyon storage facility spewed about 109,000 metric tons of methane into the air and led to the temporary relocation of about 7,000 Porter Ranch-area residents. The leak was not capped until February 2016.

The leak led to mass complaints of health issues ranging from headaches and nosebleeds to nausea and cancer; issues that persisted after the leak was capped.

Gas injections resumed at Aliso Canyon in July 2017 despite court efforts from Los Angeles County officials to block them.

In May of 2019, an independent report commissioned by the CPUC determined that a ruptured well casing and a lack of proper safety regulations were the cause of the leak.

This past May, in a largely symbolic move, the Los Angeles City Council unanimously called for the permanent closure of the Aliso Canyon. In 2019, California Gov. Gavin Newsom also directed the CPUC to expedite Aliso Canyon’s closure.

In September, Sempra Energy, the parent company of SoCalGas, reached a $1.8 billion settlement with 35,000 people who were impacted by the methane leak. While in August of 2018, officials with the state of California and the city of L.A. reached their own $119.5 million settlement with SoCalGas over the methane leak.

The governor’s office released a statement Thursday night that said they are working toward a path of shutting down the Aliso Canyon facility, but until that happens, they have to work to meet the state’s current energy needs.

(© Copyright 2021 CBS Broadcasting Inc. All Rights Reserved. City News Service contributed to this report.)