Massive Aliso Canyon methane leak finally sealed

The giant gas leak at Aliso Canyon, California that has spewed roughly two million tonnes of methane into the atmosphere has been sealed.

State regulators confirmed Thursday afternoon that the well at the Southern California Gas Co. (SolCalGas) Aliso Canyon storage facility has been permanently sealed and taken out of service.

The damaged well near Los Angeles began leaking huge amounts of methane into the atmosphere in late October, and drew comparisons to Deepwater Horizon for the months-long struggle by engineers to control the damage.

SolCalGas started drilling a relief well in early December in order to stop the gas leak by plugging the leaking well near its base.

The company still has yet to determine what caused the leak.

“Now that DOGGR (California Division of Oil, Gas and Geothermal Resources) has confirmed that the well is permanently sealed, the operations focus will shift to investigating the cause of the leak,” said Dennis Arriola, chairman and president of SolCal Gas.

“We will continue to cooperate with state regulators and an independent investigator as they work to investigate the cause of the leak.”

The Aliso Canyon storage facility provides power to the Los Angeles Basin. Because of the leak, some 4,400 residents of the city’s Porter Ranch neighbourhood had been relocated temporarily.

Although methane is a an odourless gas, mercaptans — a chemical added to help detect methane leaks — carries a strong sulphur smell that has been causing headaches, nausea and nosebleeds.

The company is facing four misdemeanor charges in connection with the leak as well as a civil lawsuit, alleging that the company violated safety laws and failed to report the leak in a timely fashion, according to CNN.

The gigantic leak caused California Gov. Jerry Brown to declare a state of emergency for the L.A. suburb of Porter Ranch.