State officials on Thursday announced that the leaking natural gas well in Porter Ranch that spewed plumes of methane and other compounds into the atmosphere has been sealed.

“We have good news. The Division of Oil and Gas has confirmed that the leak in the Aliso Canyon storage field is permanently sealed,” Jason Marshall, chief deputy director of the state Department of Conservation, said at a news conference at a Southern California Gas Co. office in Chatsworth.

The news put an end to four months of foul air that sickened many residents and forced thousands of people to relocate to temporary housing far from the leaking well. Crews reached the leak last week and injected heavy fluids and then cement to seal it.

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Dennis Arriola, president and chief executive of Southern California Gas, said the company would develop a plan to mitigate the damage the leaking well did to the environment and will support “forward-looking” regulations.

“To the residents of Porter Ranch and the surrounding communities, I want to tell you I recognize the disruption that this gas leak has caused to your lives,” Arriola said. “I know there is nothing that I can say that will change the past, but I know that measurable actions actually speak louder than words.”

The company said in a statement that the leaking well had been taken out of service. A local assistance center that will help residents and businesses recover from the leak will open Friday morning at the Mason Recreation Center in Chatsworth.

Residents who moved out of their homes were notified by phone, text and email Thursday morning that they have eight days to vacate their temporary housing that the gas company has been paying for. By early Thursday, residents of 1,800 households had returned to their homes, said Gillian Wright, vice president of customer service for the utility.


An estimated 4,000 reimbursement checks were to be issued on Thursday to residents who incurred expenses related to the gas leak, she said.

The gas company will be required to do a full inspection and testing of the other wells at Aliso Canyon before injections can resume. State authorities will continue to look into the cause of the leak, which was first reported Oct. 23.

“We will investigate what happened,” Marshall said at the news conference.

One health official said Thursday that he believes it is safe for Porter Ranch residents to return to their homes.


Jeffrey Gunzenhauser, interim health officer for the Los Angeles County Health Department, said that if residents come home and don’t smell any odors and don’t have any symptoms, it is safe to stay in their homes.

The South Coast Air Quality Management District and the California Air Resources Board will continue to monitor the air in the coming weeks, looking at the levels of methane, mercaptans, benzene and hydrogen sulfide.

“My conclusion is that all the levels that we’ve looked at are below health levels of concern, so we do not anticipate that there will be any long-term health effects in the community,” Gunzenhauser said.

As residents return home in the days and weeks ahead, attention will turn to the full scope of the damage done to the San Fernando Valley community of 30,000 people. Chief among their concerns are the effects that the worst natural gas leak in U.S. history will have on property values and residents’ long-term health — despite assurance from public officials that the noxious fumes posed no permanent health risks.


On Thursday, lawmakers and activists said that although they were glad the leak had been capped, there was still much work to do.

Rep. Brad Sherman (D-Porter Ranch) called for “tough new regulations” for the other 114 injection wells at the 3,600-acre underground natural gas storage facility, which is among the nation’s largest. The gas company has said that many of those wells are aging, corroded and mechanically damaged.

Sherman, in a statement, called for subsurface safety valves on each well and for 24-hour monitoring of each well that could be viewed online by the public. He said the Aliso Canyon facility should remain closed “until we know it is safe.”

“We should not be declaring victory, as the Aliso Canyon facility and the negligence of Southern California Gas Company continue to pose a threat to the community,” Sherman said. He criticized the gas company, saying that even though it has encouraged residents to return, “truly thorough indoor air testing has not yet been completed.”


State and local officials this week expressed concern that contaminants might linger in the area and called for new criteria to determine that the air has returned to normal before residents return.

Of particular concern is the presence of four pollutants: methane, which is not considered toxic to humans but is a potent greenhouse gas; mercaptans and hydrogen sulfide, which at extremely low levels can cause ailments including headaches and nausea; and benzene, a known cancer-causing compound.

Los Angeles City Councilman Mitchell Englander, who represents communities affected by the leak, called for a comprehensive, independent study of potential health impacts.

“This is not the end of this catastrophic disaster, this is the beginning of the next chapter,” he said in a statement.


The gas company is facing ongoing investigations by the state attorney general’s office and the Los Angeles city attorney’s office, dozens of lawsuits for economic damages, and the possibility of environmental fines connected to the well’s release of an estimated 80,000 metric tons of mostly methane into the atmosphere.

The company 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. The company has pleaded not guilty.

“It’s woken the community up to the fact that there are dozens of other wells,” said Randall Bell, an appraiser who is working with attorneys to determine what may happen to property values in Porter Ranch. “Now the community is wide awake to that issue.”

With the damaged well sealed, the city’s Emergency Management Department will lead recovery efforts by coordinating with local, state and federal agencies. City officials plan to open a temporary office in the community, though a location has not yet been announced.


“The recovery process for a community is often fraught with uncertainty,” said the department’s general manager, James Featherstone.

Environmental activists are calling for permanent closure of the field they say is emblematic of the dangers involved in satisfying the nation’s fossil-fuel addiction.

Matt Pakucko, president of the community group Save Porter Ranch, said in a statement Thursday that residents “have suffered long enough and shouldn’t be subjected again to a similar disaster.”

“It is unacceptable to allow SoCalGas to reopen this facility,” he said.


alice.walton@latimes.com | Twitter: @TheCityMaven

hailey.branson@latimes.com | Twitter: @haileybranson

louis.sahagun@latimes.com | Twitter: @LouisSahagun

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