California declares massive gas leak sealed after 16 weeks

At its height, the escaping gas at the Aliso Canyon storage field accounted for a quarter of all methane emissions – an extremely potent greenhouse gas – across the entire state of California.

Jason Marshall, chief deputy director of the California Department of Conservation, said it was safe for residents to return, and that the utility had agreed to continue paying their relocation expenses through next Thursday morning.

The Oil, Gas, and Geothermal Resources agency will be expected to confirm that the flow of gas has stopped once the company completes sealing the leaking well with cement. But Southern California Gas Company, the company managing the well, was reluctant to predict when the state would declare the leak officially over.

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

SoCalGas CEO Dennis Arriola, second from right, takes questions from the media Thursday, Feb. 18, 2016, during the announcement that the Porter Ranch gas leak has been permanently sealed during a news conference in Chatsworth, Calif., on Thursday, Feb. 18, 2016.

SoCalGas has furnished temporary housing to some 4400 Porter Ranch residents. “We are committed to earning back their trust and confidence over time through our actions, not our words”.

With gas in California’s air and lead in Michigan’s water, crumbling infrastructure and weak regulation are putting people at risk across the country, say environmental campaigners.

The well is no longer releasing any gas or odorant, and “residents should no longer experience short term health symptoms related to the release of odorants from the gas well”, the utility said.

After the arraignment, SoCalGas spokesman Mike Mizrahi said: “When we discovered the leak, we made prompt notification to multiple agencies….” With the leak capped, many of those displaced will have a week to return home.

The natural gas leak, one of the largest in U.S. history, has caused thousands to relocate.

Some residents angry or sickened by the leak want to see the storage area permanently closed.

California Governor Jerry Brown declared a state of emergency in the area in January.

Rep. Brad Sherman, D-Sherman Oaks, who represents a portion of Porter Ranch residents, said today in a statement that he is pleased the leaking natural gas well has been sealed, but said the development is not a victory. It also faces four criminal charges from the L.A. County district attorney’s office for failing to report the release of hazardous materials and discharging air contaminants, to which the company has pleaded not guilty.

Many residents of Porter Ranch and neighbouring communities, literally sick of the whole affair, think both sides are at fault, accusing them of an “incestuous” relationship.

The utility has paid to relocate 6,400 households.

Air quality monitors set up during the leak will remain in place to make sure the air is clean to breathe.