Gas continued to flow into San Bruno for nearly two hours Thursday after a pipeline exploded, fueling the fire as it destroyed dozens of homes.
It took 106 minutes for PG&E to shut off the manual valves supplying gas to the pipe after the early evening explosion despite a 1980s warning for PG&E to improve pipe shutdown practices.
On Tuesday, a lawmaker called on the utility company to install automatic shut-off valves throughout its entire gas transmission network.
The National Transportation Safety Board (NTSB) is investigating PG&E’s response in shutting down the pipeline valves, which were between 1 and 2 miles of each side of the explosion site.
“For awhile, it was frankly just not safe to be able to access the valves,” PG&E Vice President Geisha Williams said during a San Bruno town hall meeting Monday evening. Manual valves were located in the area of last week’s deadly blast. Regulators do not require the use of automatic valves.
A manual high-pressure pipeline can only be closed once the pipeline has been depressurized and once the site is unlocked and considered safe.
In the wake of last week’s disaster, California utilities regulators are considering mandating the use of automatic valve shut-off technology.
On Tuesday, Assemblyman Jerry Hill, D- San Mateo, said he would work with regulators or introduce legislation to mandate the automated technology.
“In San Bruno, it could have saved property damage and possibly lives,” he said.
The NTSB is inspecting the affected pipeline’s valves.
It’s also investigating whether PG&E properly trained its operators to switch them off and whether the valves had been regularly tested and exercised.
The board is also interviewing PG&E officials who were working in control centers overseeing the pipeline network. The officials tested negative for drugs and alcohol, the NTSB said.
The same safety board in 1982 admonished PG&E and recommended that it improve its valve-closing procedures in the wake of a prolonged gas leak, which did not explode, in downtown San Francisco.
The board urged PG&E to provide training on closing valves to a wide range of employees and ensure that all valves are inspected and operated annually.
The Aug. 25, 1981, leak lasted 20 minutes longer than it would have lasted if the company’s personnel were better trained, the board found.
State Sen. Leland Yee, D-San Francisco-San Mateo, said Tuesday he will introduce legislation to provide disaster relief.
PG&E is asked to reveal where pipelines run
By Katie Worth
Examiner Staff Writer
Leaders from San Francisco and throughout California are demanding that PG&E provide information about the location and maintenance status of its natural-gas pipelines.
Three San Francisco supervisors introduced separate resolutions Tuesday to force PG&E to provide information about the location of gas transmission pipes and their shut-off valves, their vulnerabilities, their ages, and their maintenance and inspection schedules, as well as the details of the utility’s disaster response strategies.
Meanwhile, state Assemblyman Jerry Hill and U.S. Rep. Jackie Speier sought information about PG&E’s list of the 100 most-vulnerable pipelines, a list mentioned in a filing with the California Public Utilities Commission last year but never revealed.
U.S. Sens. Dianne Feinstein and Barbara Boxer have demanded an investigation of all interstate gas pipelines in California.
Supervisors Sophie Maxwell Carmen Chu and Ross Mirkarimi each introduced local legislation demanding information from PG&E, said the issue wasn’t really on anyone’s radar until last week’s deadly blast in San Bruno. The City’s Department of Emergency Management, Fire Department, Department of Public Works and Public Utilities Commission have all said they do not have maps of PG&E’s pipelines, despite federal regulations obligating utility operators to provide this information.
The explosion and fire’s terrible toll
4 Confirmed dead
37 Homes destroyed
19 Homes substantially damaged
321 Homes with minor damage
314 Homes reoccupied by Tuesday morning
$100M PG&E assistance pledged
Sources: San Bruno, PG&E