More than 45 minutes after all hell broke loose when a 30-inch diameter natural gas transmission pipeline ruptured last September, Pacific Gas and Electric Co.'s (PG&E) pipeline system control center was still unsure about the extent of the problem and whether it involved the utility's transmission pipeline, according to a 441-page transcript that was one of hundreds of records made public Tuesday at a National Transportation Safety Board (NTSB) hearing. It began three days of fact-gathering in Washington, DC.
The lack of clarity among the pipeline operating staff is not surprising given the fact that PG&E early in the aftermath said it took field mechanics more than 90 minutes to close the pipeline valves on either side of the rupture of its Line 132, one of three major north-south transmission pipelines running through the area. But the absence of automatic shutoff valves -- the subject of much questioning and conjecture at Tuesday's opening NTSB hearing -- is all the more striking in the wake of a more recent gas transmission pipeline rupture Feb. 19 on TransCanada's Mainline in a rural portion of Ontario in Canada (see Daily GPI, Feb. 23). In that incident automatic shutoff valves isolated the rupture by shutting down the line in five minutes.
Even at 7:06 p.m., more than 50 minutes after the incident in San Bruno, the PG&E pipeline engineering executive in charge, Kirk Johnson, is recorded asking gas control about reports of a plane crashing into the utility's pipeline. And earlier, reports were circulating in the gas control transcript that a nearby gasoline station in the area was cited as the cause of the explosion and fire.
Gas control appeared to have no access to news media coverage and was dependent on calls from other employees who were monitoring local broadcast outlets at the scene.
The utility's emergency response was one of four major issues that PG&E attempted to address at Tuesday's NTSB hearing. The San Francisco-based combination utility said it was now "taking many additional steps to strengthen" its emergency response system. And one of those steps is to "enhance" its gas control practices and procedures, the utility said.
"PG&E has a well established set of plans and protocols for contacting emergency first responders and working with its communities to ensure an effective response," a utility spokesperson said. In the wake of the death and destruction caused by the San Bruno blast PG&E and NTSB have emphasized more and better information sharing with local authorities, and San Bruno elected officials have been demanding it in PG&E's case.
(The San Bruno mayor and one of its city council members attended the NTSB hearing and were able to question utility representatives as part of the federal board's hearing format.)
The other issues centered on remote shutoff valves, pipeline integrity management systems and record keeping, all areas that PG&E has received criticism about from regulators, elected officials and the news media. The utility's lack of automatic valve-closing capability on the transmission line that failed was a major source of questioning at the NTSB hearing.
In response, PG&E's spokesperson afterward tried to emphasize that the utility's 5,700-mile transmission pipeline system includes a number of automatic/remotely operated shutoff valves. "PG&E is working with industry experts to study the best use of these valves and significantly expand their use where appropriate."
Part of the testimony to NTSB said PG&E now is piloting the installation of 12 new remote valves this year and will be filing a plan with the California Public Utilities Commission to substantially increase their use.
Nevertheless, NTSB investigators grilled one of the PG&E engineers testifying, Chih-hung Lee, a senior consulting gas engineer, who five years ago completed an internal analysis that concluded there was no safety advantage to adding remote valves on Line 132, the rupture of which caused much mayhem on Sept. 9 last year.
"We continue to learn from the tragedy in San Bruno and adapt our operations based on the findings of various reviews, including the NTSB's investigation as well as our own," said PG&E utility President Christopher Johns, who attended the hearing on Tuesday. "We intend to share the lessons we learn with the industry to enhance gas safety across the United States."
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