San Carlos and PG&E officials on Monday said that a natural gas pipeline that city leaders feared could be unsafe has been closed off from the transmission system and reduced in pressure.
While the 3.8-mile-long Line 147 has been shut off from receiving gas, it has not been fully shut down.
Instead, the pressure inside the pipe has been reduced from about 300 pounds per square inch to 120 pounds per square inch, said PG&E spokeswoman Brittany Chord.
Chord said PG&E workers completed isolating and deactivating Line 147 at about 10 p.m. Sunday and finished reducing the pressure Monday.
Representatives of both sides said they think the line is safe for the time being and that the action complies with a San Mateo County Superior Court judge's order Friday that required PG&E to "immediately shut off service" to the line "in a safe and effective manner."
"We're comfortable with the situation for now," said City Manager Jeff Maltbie.
"We feel that fulfills the court order," said Chord, who also said, "We believe the pipeline is and was operating safely."
Chord and Maltbie said the reasons for keeping low-pressure gas in the pipe instead of fully emptying it are to enable PG&E to reactivate it more easily if it is needed and to help protect the integrity of the pipe.
The lower pressure and isolation of the line reduce the risk of a catastrophic explosion, Maltbie said.
Judge George Miram issued the temporary injunction late Friday in response to an emergency request from the city.
San Carlos sought the order after receiving a set of internal emails from PG&E Thursday that showed that unidentified PG&E engineers expressed concerns last year that the 1929 pipe was thinner than stated in PG&E records and had shown recent corrosion.
One engineer wrote on Nov. 17, 2012, "Are we sitting on another San Bruno situation?...Is the pipe cracked and near failure?"
In San Bruno, an explosion of a PG&E natural gas pipeline and ensuing fire on Sept. 9, 2010, killed eight people, destroyed 38 houses and damaged dozens of other buildings.
The PG&E engineer also wrote, "I don't want to panic people but it seems like we should consider this and probably move this pipe up the PG&E PSEP (Pipeline Safety Enhancement Plan) priority for replacement."
Another engineer wrote in a Nov. 15 email that a repair last year of a leak in Line 147 showed that the pipe's actual specifications were "inconsistent with current data in the PG&E system."
The emails about the San Carlos line surfaced in connection with a California Public Utilities Commission proceeding that is being undertaken in the wake of the San Bruno disaster.
The purpose of the proceeding is to determine whether PG&E's record keeping on pipelines was unsafe and illegal and if so, to determine a penalty.
The proceeding is one of three being conducted in connection with the San Bruno explosion. The other two are to determine a penalty for violations that led to the San Bruno event and to consider alleged violations in pipeline classifications.
San Carlos Public Works Director Jay Walter said the city received the emails after CPUC staff sought and won an order from commission administrative law judges requiring PG&E to disclose to the staff some internal emails related to discrepancies in pipe records.
In addition to giving the emails to the CPUC investigators, the utility voluntarily released them to San Carlos, Chord said.
"This is about the culture PG&E is trying to build that puts
safety first and encourages employees to come forward with questions or issues," Chord said.
Maltbie said, however, that PG&E had never disclosed the emails to San Carlos officials in previous meetings and discussions, including a Sept. 16 conversation in which a PG&E official allegedly assured the city that Line 147 was safe.
"They had no intention of releasing the information if not ordered to by the PUC," he said.
The engineers' names and some details about the pipe specifications were blacked out of the email copies given to the city.
The city manager said he hopes the next steps will be that PG&E will provide more information on the pipe and that the CPUC will hold hearings on the safety of the pipe. City representatives met with a CPUC staff member today to convey their concerns, he said.
There will also be another hearing before Miram in Superior Court on Oct. 24.
Chord said the utility believes Line 147 is safe because it was hydro tested with high-pressure water in 2011 and also given metallurgy tests after a leak was repaired last year.
She said city residents are currently receiving adequate natural gas supplies, but the utility hopes to be able to reactivate the pipe before winter to meet the increased energy demand during cold weather.
Mayor Bob Grassilli said in a statement, "I am thankful that PG&E shut the line down on Sunday in compliance with Judge Miram's order, and with the compromise plan that has been reached, for now.
"We appreciate the effort PG&E has taken to achieve this shutdown condition, as it also minimizes the impact and risk to our residents," Grassilli said.
Meanwhile, San Bruno city leaders are stunned by what has unfolded in San Carlos.
San Bruno City Manager Connie Jackson is committed to pipeline safety.
"This can't happen again, we don't want anyone to experience what happened in San Bruno," she said.
Jackson said it's disheartening to learn PG&E has known about safety concerns in San Carlos for more than a year, but the emails and information are just now surfacing. Jackson is now drafting a letter she plans to send to cities all over California urging city leaders to pressure PG&E to reveal what else it knows.
NBC Bay Area's Jean Elle contributed to this report.