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PG&E pledges crackdown on repeated pressure surges

Jaxon Van Derbeken, San Francisco Chronicle, May 20, 2012

Pacific Gas and Electric Co. has accidentally over-pressurized pipelines on its gas system more than 120 times since the San Bruno explosion - a rate that the company's top gas official says is unacceptable and that experts fear could increase the risk of a similar disaster.

The San Bruno tragedy happened after an unexpected gas pressure surge ruptured a substandard weld under the Crestmoor neighborhood in September 2010. The blast and resulting fire killed eight people and destroyed 38 homes.

This year, federal rules went into effect requiring utilities for the first time to track and report instances in which pressure goes over a pipeline's designated maximum by a significant amount. Although many of PG&E's incidents are comparatively minor, the head of its gas operations said the company's track record since San Bruno is nonetheless disturbing.

'Not supposed to occur'

In a May 2 internal e-mail, gas-division chief Nick Stavropoulos said the company had already recorded 40 pressure surges this year, on top of 78 last year. Since then, there have been at least three more, the company said in a statement last week.

"We're really going to crack down" on such problems, Stavropoulos said in the e-mail, which The Chronicle obtained from a source.

Stavropoulos, who has spent more than 30 years in the gas industry and joined PG&E after the 2010 disaster, wrote that "over-pressurizations are not supposed to occur. If we're doing our jobs correctly, we should have such tight controls in place that they simply don't happen. And if they do, they are supposed to be an exception, not a norm."

Richard Golomb, who advises pipeline companies on pressure-control valves and their placement, agreed that over-pressurization incidents are rare for most operators. Having an excessive number of them, he said, is a warning sign about the health of a pipeline system.

"They happen - but you have to find out what happened, why it happened, so you can prevent it," Golomb said.

Asked about PG&E's total, Golomb said, "That shouldn't be. Pressurization has to be controlled - that's the whole idea of the system."

The most likely explanations are bad engineering, poor maintenance or both, he said.

"They've got a serious problem," Golomb said, speculating that the cause was "neglect, absolute neglect."

Danger on Peninsula

A study done for PG&E on the line running through San Bruno and two other transmission pipes on the Peninsula found that over-pressurizations were a significant threat, given that all are several decades old and some have stretches of much lower-quality pipe than is standard today.

Repeated pressure surges, the study found, increase the risk of failure on older parts of lines that have already exceeded their predicted life span.

The report, issued in March, concluded: "Protection against over-pressurization events is important."

PG&E logged seven major surges in pressure on transmission lines in 2008, seven in 2009 and two in 2010. By comparison, California's other two major utilities, Southern California Gas Co. and San Diego Gas and Electric, had two and zero surges, respectively, during those years.

The most serious of PG&E's recent surges occurred at the Topock compressor station at the Arizona border, where natural gas coming into the state is funneled into two main lines running up the Central Valley. PG&E cut pressure at the station after the February 2011 surge, then inspected the system using high-pressure water before restoring the line to full strength last fall.

The California Public Utilities Commission said in a statement that the agency was aware of PG&E's pressure surges and would investigate them.

Neighborhood surges

A majority of this year's surges have happened on distribution lines, the pipes that snake through neighborhoods and deliver gas to individual homes and businesses.

Surges on distribution pipes are "of particular concern, since there isn't a regulator between the gas main and the house or business," Stavropoulos wrote in the e-mail, referring to devices that control excess pressure. Transmission lines, the larger pipes that feed distribution systems, always have the devices.

PG&E had a target of no more than 42 accidental surges this year on its almost 50,000-mile gas system, Stavropoulos wrote. The company recently surpassed that number, less than halfway through 2012.

"That's not a good thing," he wrote. "In fact, it's the kind of thing that keeps me up at night."

Stavropoulos said "human performance plays a large part" in surges, but the company also needs to do more to make sure pressure-regulating devices are properly calibrated and functioning.

Most surges small

In an interview, Stavropoulos stressed that most of PG&E's surges have been small. The company said in a statement that the majority of last year's spikes were less than 10 percent over the pressure maximum set by PG&E.

But Stavropoulos said any such "excursion" is unacceptable.

Stavropoulos said that at other utilities where he has worked, "we hardly had any" pressure surges, even small ones. But PG&E has long considered pressure surges to be "a little noise in the background and not sort of a problem," he said.

"The way I look at it, an excursion is an excursion - I'm a stickler for detail," Stavropoulos said. "With the focus we have on safety and compliance, we have to draw the line and say, 'We expect perfect performance, and this is an important area.'

"Companies that are top in class in safety and compliance have these bright-line rules," he said. "That's what we're trying to instill here."

Stavropoulos said his e-mail had been well received by company engineers who thanked him for setting definitive standards.

Experts expressed fear that pressure surges - even small ones - are just the latest sign that PG&E is still unable to operate its system safely.

"If you don't have control of pressure, it's not a question of if, but when," another San Bruno blast happens, said Richard Kuprewicz, a pipeline safety expert who advises a ratepayer organization, The Utility Reform Network. "This is something where the regulators need to be right on it, No. 1 priority, now."

John Gawronski, a former New York state regulator and expert on pipeline safety, said in a recent regulatory filing aimed at assessing the company's safety regimen that he has concerns across the board about PG&E's record.
'I have little confidence'

"The San Bruno investigation shows that PG&E did not respond appropriately to the increasing levels of uncertainty present in its pipeline system," Gawronski wrote. "In light of all of these facts, I have little confidence that PG&E has been providing safe and reliable service."

Stavropoulos said the response to his e-mail gives him optimism the company will get a handle on the problem, but he remains vigilant.

"I worry about everything - that is my job," he said. "Until we get down to zero, I'll still worry. ... I'm worrying until I feel we can put this to bed."

Jaxon Van Derbeken is a San Francisco Chronicle staff writer.


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