PG&E to give heads-up to people near big gas lines
By Jaxon Van Derbeken
San Francisco Chronicle
March 4, 2011
Pacific Gas and Electric Co. has agreed to send letters to thousands of customers telling them they live within 2,000 feet of a gas-transmission line, Rep. Jackie Speier said Thursday.
The Hillsborough Democrat, whose district includes the San Bruno neighborhood devastated when a PG&E transmission line exploded Sept. 9, said she met with utility President Chris Johns on Wednesday and that he had committed to notifying customers who are near transmission pipes.
Company spokesman Joe Molica confirmed Thursday night that PG&E would send the letters, saying the idea is to “make it easy for anyone to learn about pipelines in their area.”
Johns also said PG&E will soon begin installing automatic shutoff valves on pipelines that cross earthquake faults, according to Speier. As many as a dozen of the valves will be placed on the Peninsula, she said.
If PG&E follows through, Speier said, “they become the gold standard for how to operate a utility moving forward, in terms of safety.”
Shutoff valves
The subject of automatic shutoff valves came up repeatedly during three days of hearings into the blast this week by the National Transportation Safety Board, because PG&E had only manually operated valves on the San Bruno pipeline.
PG&E officials conceded that automatic valves could have shut the flow of gas to the rupture within 15 minutes, compared with the nearly hour and a half it took workers to reach the manual valves and close them.
The cost of automatic valves has been put at anywhere from $100,000 to $1.5 million each. Speier said she understands rates may go up for consumers.
“I’m one of those consumers,” Speier said. “And you know what, if it means safety for my family and for my community, that is the price we have to pay.”
She added, “No one should have to wait an hour and a half for the gas to be turned off to be able to fight a fire.”
Both PG&E’s decision on the valves and planned notification to residents living near transmission lines followed embarrassing revelations for the utility during the safety board’s hearings.
Engineer’s conclusion
PG&E officials had ruled out the widespread installation of automatic valves, based in part on a company engineer’s 2006 memo asserting that most damage from transmission line ruptures takes place within 30 seconds. The engineer, Chih-Hung Lee Sr., testified Tuesday that he had based his conclusion on industry studies and ignored a federal study showing the valves had benefits.
On Wednesday, San Bruno Fire Chief Dennis Haag testified that he hadn’t known a gas-transmission line ran under his city until the pipe exploded. PG&E’s public-notification measures on gas-safety tips also came in for criticism when an executive admitted that the company had recently mailed safety surveys to 15,000 customers and received just 20 replies.
Speier has sponsored legislation to require that all customers living within 2,000 feet of transmission lines be notified in letters.
Deborah Hersman, chairwoman of the federal safety board, praised PG&E’s actions, saying they were a welcome change from the company’s “abysmal track record” in public-notification efforts.
“This is exactly the type of progress we could hope for at a hearing like this,” Hersman said. “These are the direct benefits of having this conversation in the public eye.”
San Bruno blast an ‘anomaly,’ industry exec says
By Jaxon Van Derbeken
San Francisco Chronicle
March 4, 2011
The pipe defect implicated in the deadly explosion of a Pacific Gas and Electric Co. natural gas transmission line in San Bruno was an “anomaly” that does not necessarily signal a broader danger for gas companies or their customers, an industry executive testified Thursday.
An investigator on a National Transportation Safety Board panel looking into the disaster took issue with the remarks by Christina Sames, vice president of the American Gas Association, saying there may indeed be a pattern that amounts to a public safety hazard.
The exchange touched on an issue that came up repeatedly in three days of hearings into the San Bruno explosion and fire Sept. 9, in which eight people died and 38 homes were destroyed – whether pipeline companies need to do more rigorous and costly inspections of pipes to find defects that can cause disasters decades after the lines were put in the ground.
Sames, whose group represents PG&E and 200 other gas-distribution companies nationwide, was asked about a flawed weld that federal metallurgists have concluded was the starting point of the San Bruno rupture. The longitudinal seam weld extended only halfway through the 1956-vintage pipe’s wall, but PG&E never conducted the type of test that would detect such a flaw.
Federal law allows pipeline operators not to test pre-1970 gas transmission lines for such problems. Ravi Chhatre, the investigator leading the safety board’s probe of the explosion, asked Sames how, in the absence of such inspections, the industry could be sure similar dangers were not lurking in other pipelines.
Mississippi explosion
“When I look at the statistics of incidents, I am not seeing that as an issue,” Sames said. “I’m seeing what happened in San Bruno as an anomaly. And what we in the industry are hoping is that your investigation will find out why that occurred.”
But safety board chief pipeline investigator Robert Trainor noted that a liquid-propane pipeline that exploded in Carmichael, Miss., in 2007, killing two people and injuring seven, also had a flawed seam weld.
“Within the last five years, we have had two accidents that claimed 10 lives,” Trainor said. “I question whether these two accidents should be considered anomalies.”
Sames answered, “You look at the history of incident data, which is more than 20 years. You are talking about two incidents out of hundreds? To me that is still an anomaly.”
City official objects
San Bruno City Manager Connie Jackson, representing the city at the hearing, told Sames that she took “strong exception” to the characterization. San Bruno residents would find it a “very difficult position or conclusion to accept, if only because it could diminish the urgency” of dealing with the problems in the gas-transmission system, she said.
Sames replied that she wasn’t trying to “diminish the magnitude” of the disaster or discount the importance of learning lessons from it.
Sames was on a panel of experts testifying about pipeline technology and inspection practices as the federal safety board wrapped up its hearings.
PG&E inspected the San Bruno line in 2009 using a method known as direct assessment, which measures corrosion by using ski-pole-like devices that electronically map hot spots from ground level. The method is intended mainly to find corrosion and was blind to the flawed weld that has become the center of the San Bruno investigation.
Few choices
High-pressure water testing is the only sure way to vouch for the safety of old, bending lines that make up an estimated 61 percent of the U.S. gas transmission network, the experts testified. PG&E and other pipeline operators are reluctant to use it, however, because it forces them to shut down pipelines for days and costs as much as $500,000 per mile.
But new robotic technology coming as soon as next year could give companies an alternative, said Robert Smith, head of research for the federal pipeline safety agency.
“The future is bright and promising,” Smith said.
He touted a self-propelled robotic method being developed for lines considered off-limits to smart pigs, automated devices with electric sensors that are run through pipes to look for manufacturing flaws such as bad welds.
Smart pigs have difficulty negotiating lines with sharp turns, and PG&E intends to use them to inspect just 20 percent of its 1,021 miles of pipeline in urban areas. The company is planning to use direct assessment for the rest.
Paradox in law
Michael Budinski, a safety board investigator, pointed to what he saw as a paradox in federal regulations – that pipeline companies must know what threats their lines face before selecting an inspection method to find them.
Budinski called it “an unending loop – you almost need to inspect the pipeline first so you can figure out what threats to identify, then start to monitor those threats.”
Federal officials said the San Bruno explosion was just one of several recent accidents in which companies incorrectly assessed the dangers its pipes faced. They plan workshops for this summer on how companies can comply with the federal inspection regimen and have announced they will join California regulators in auditing PG&E’s safety practices.
Alan Mayberry, field operations administrator for the federal Pipeline and Hazardous Materials Safety Administration, said his agency also is considering rules to bar the kind of pressure spikes that PG&E used on the San Bruno line and other older pipes.
The company believed it had to run the pipes at the legal maximum at least once every five years or risk having those pressure caps reduced. Several experts have said the practice may weaken pipelines, although PG&E insists it is safe.
Following rule’s intent
Mayberry said federal regulators did not envision companies conducting such pressure spikes when they wrote the rules implementing a 2002 inspection law.
“That was not the intent when the regulation was written,” Mayberry said. “Perhaps that act, in and of itself, may create the need to inspect for” defects such as the flawed weld found after the San Bruno blast.
“We take incidents like this and learn from them,” he said.
San Bruno blast: Watchdog criticizes PG&E spikings
By Jaxon Van Derbeken
San Francisco Chronicle
March 3, 2011
A top gas-safety regulator for California called Pacific Gas and Electric Co.’s practice of intentionally spiking the pressure on older urban gas pipelines “a wrong-headed approach to safety” on Wednesday, and he would not dismiss the possibility that it contributed to the deadly San Bruno explosion.
Richard Clark, head of the state Public Utilities Commission’s consumer protection and safety division, attempted to distance his agency from PG&E’s practice on the second day of a National Transportation Safety Board hearing looking into the explosion that killed eight people and destroyed 38 homes.
PG&E says it needed to push pressure on some of its older lines to the legal limit once every five years or risk having that limit reduced, and that the practice was safe. On the gas-transmission line that ruptured in San Bruno, the utility surged pressure to just over the maximum allowable in 2003 and in 2008.
Several critics of the practice have told The Chronicle that such spikes could weaken a pipe and make it more prone to rupture. PG&E recently told investigators that one reason for the intentional increases was to avoid a situation where the utility would have to shut down a pipeline for a lengthy and costly test for problems such as weak welds, using high-pressure water.
Avoiding assessment
Federal investigators say the Sept. 9 blast in San Bruno began at a badly constructed weld on the pipe’s seam.
“So by running up to their (maximum legal pressure level), they are not having to do that type of assessment?” Matt Nicholson, an investigator for the federal safety board, asked the California regulators.
“I want stress that’s PG&E’s interpretation,” Clark responded. “They did not come to us and ask us our opinion about that. We’re not in accord with that interpretation.”
“What is your interpretation?” asked the board’s chairwoman, Deborah Hersman.
Clark said California regulators believed that “artificially raising pressure in a pipe that has identified integrity seam issues (weld flaws) seems to be a wrong-headed approach to safety.”
Clark added, “As to whether or not it would cause stresses on the pipe that would result in a fracture … raising it incrementally once every five years, is a matter for metallurgists to decide.”
Hersman asked Clark and other members of a witness panel whether PG&E’s practice was common in the gas industry.
“We’ve not seen it before,” Clark said.
“We’ve definitely not seen it before,” added a federal pipeline safety official, Linda Daugherty.
Grandfathered rules
Paul Metro, representing a national group of pipeline safety inspectors, agreed that it was “an anomaly.”
“We’ve haven’t seen other states report anything similar to this,” said Metro, vice chairman of the National Association of Pipeline Safety Representatives.
PG&E said that in the instances when it exceeded legal caps on the San Bruno line, it did so by only “a few pounds” of pressure. It says it has halted the intentional surges since the disaster.
The maximum pressure level on the San Bruno line was set under a 1970 federal law that allowed companies to avoid testing pipelines that were already in the ground. As much as two-thirds of PG&E’s 5,700-mile network of transmission lines falls into that category.
Daugherty, a safety programs administrator at the federal Pipeline and Hazardous Materials Safety Administration, suggested that it was time to rethink that law. Pre-1970 lines that were “fairly new” at the time are well into middle age now, she noted.
“We are now a ways down the road, and we need to revisit where the grandfather clause is still appropriate,” Daugherty said.
Any change could have major repercussions for PG&E and its customers. Many of the utility’s lines would have to be tested with high-pressure water, which requires that a pipe be shut down for days. The utility has estimated the cost of such testing at as much as $500,000 per mile.
Policing PG&E
What’s more, such testing is most often done now before a pipe is put in the ground. Clark noted that operators “go to great lengths to keep water out of their pipes,” because it can cause corrosion that eats away at metal walls.
Much of the discussion at the hearing focused on how well Clark’s agency is policing PG&E.
Clark said the state Public Utilities Commission is obligated to inspect natural gas operations at 2,800 mobile parks once every five years and does audits of PG&E and other utilities “as our resources allow.”
For the seven years before the San Bruno disaster, federal regulators found that the state agency had not dedicated enough resources to gas pipeline inspections, The Chronicle has reported. In 2006, federal officials warned the state that it was putting public safety at risk.
Julie Halligan of the state commission’s safety arm testified Wednesday that the agency has done only four audits of gas transmission systems since 2004. In the wake of the San Bruno explosion, she said, the agency would like to inspect the transmission system “much more frequently.”
Regulator’s role
Clark said that given the gas industry’s “very safe” record, the agency has had trouble persuading the state to provide more inspectors. But the commission did not seek a major boost in staffing levels until after the San Bruno disaster and now has 13 inspectors.
Clark explained that he sees his role as “essentially to act as a district attorney” when it comes to seeking gas safety fines against utilities such as PG&E – something his agency has not done for more than a decade.
“You know, you make mistakes in that regard sometimes,” Clark said. “But for the most part, when we get to the point where we’re not getting compliance … or we feel that the utilities are misrepresenting the facts, then we will absolutely take enforcement actions.”
San Bruno blast: Feds find more flaws in gas line
By Eric Nalder
San Francisco Chronicle
March 3, 2011
A defective seam weld wasn’t the only time bomb lurking in the natural-gas pipeline that exploded in San Bruno in September, a newly released federal document shows.
The girth welds holding together the pipe sections at the explosion site were “rejectable by virtually every welding code in existence” and “grotesquely at odds with industry standards and specifications,” said Doug Chisholm, a pipeline consultant from Virginia who reviewed a National Transportation Safety Board metallurgy report released this week.
Sections misaligned
The report also showed that two pipe sections were misaligned and the steel wall of one pipe was of a different thickness than the others.
Photos in the report clearly showed “egregious, sloppy, careless, defective, negligent welding,” said Chisholm, a specialist in pipeline failures and chief of research for the federal Office of Pipeline Safety from 1979 to 1989.
Sloppy job
The federal safety board has determined that a weld on the seam of the San Bruno pipe ruptured, not the girth welds, which encircle a pipe.
But Chisholm said the condition of the girth welds is another indication of the sloppiness of the 1956 pipeline construction project overseen by Pacific Gas and Electric Co., which moved a portion of the line as the Crestmoor subdivision of San Bruno was built.
“It was out of control. Completely out of control,” Chisholm said of the construction project. “I don’t know who inspected this. I don’t know what the inspection protocols were. I’ve been in this business for 35 years, and these are among the worst textbook examples of girth welds I have ever seen.”
He added, “It goes to the culture of PG&E’s construction standards. Somebody wasn’t watching what was going on.”
No comment on welds
PG&E spokesman Paul Moreno declined to comment on the welds, but said that “the San Bruno accident underscores that PG&E must do a better job of managing the safety of its natural gas system.”
Chisholm and others expressed surprise the girth welds never failed, given San Bruno’s proximity to the San Andreas Fault. Girth welds are most vulnerable to earth movement, while seam welds are most vulnerable to changes in gas pressure, Chisholm said.
The existence of the shoddy welds raised questions about whether such problems could be hiding in other buried pipelines.
“It’s not the worst,” said pipeline safety consultant Richard Kuprewicz of Redmond, Wash. “I’ve seen worse. Look, you guys, this is America, without checks and balances.”
Robert Eiber, a longtime pipeline consultant from Ohio, said, “I don’t think this is typical of the whole pipeline industry. But I don’t really have a basis for saying this, other than the fact I have never run into anything like this before.”
Missing records
PG&E says it hasn’t found similar problems in its system, but it is still researching its records under orders from the California Public Utilities Commission. Before the explosion, PG&E’s computerized records indicated the San Bruno pipe didn’t have seam welds, and the company has admitted that large amounts of records for other lines are missing.
Federal reports issued since the San Bruno disaster indicate that other pipeline companies have similar documentation problems.
Officials with the federal Pipeline and Hazardous Materials Safety Administration – which is responsible for pipeline integrity nationwide – admitted during this week’s hearings in Washington into the San Bruno explosion that it lacks basic information, such as how many miles of pipeline have never been tested for weld defects. The San Bruno pipe was one of those untested lines.
Mystery welders
PG&E has been unable to find critical documentation on the 1956 project, including any indication of who did the welding. The company has speculated that the pipe came from a salvage yard, and that some might have come from sections of pipe that had failed factory pressure tests.
Seam welds are installed at the factory, and girth welds are usually installed at the construction site.
Eyewitnesses to the 1956 project are also in short supply, although one, retired PG&E employee Frank Maffei, gave federal investigators an account of an ad hoc inspection job.
“The thing I remember most,” Maffei said, “is myself and another (employee) crawled through the pipe before they tied it in, to look for debris, welding rods, tools, old lunches, jackets, wild pigs, anything.”
San Bruno’s fire chief was in dark about pipeline
By Jaxon Van Derbeken
San Francisco Chronicle
March 3, 2011
San Bruno’s fire chief said Wednesday that he was not aware before last year’s deadly natural-gas explosion that a major Pacific Gas and Electric Co. pipe ran under the city, although he acknowledged that it had been his responsibility to know.
“The situation on Sept. 9 wasn’t something that we could ever imagine,” Chief Dennis Haag said on the second day of a National Transportation Safety Board hearing in Washington into the explosion that killed eight people and destroyed 38 homes.
The fire chief was one of seven public officials and gas industry representatives who testified about the efforts that PG&E and other pipeline companies make to alert residents and local officials about gas transmission lines running through urban areas.
Many residents don’t get the word, federal officials concluded. And as Haag showed, sometimes fire chiefs don’t, either.
Haag, who also serves as chief of neighboring Millbrae’s fire department, said he had known that two PG&E gas transmission lines ran up the Peninsula roughly parallel to Highway 101 and Interstate 280, because someone told him when he was responding to an incident. He had to look up what a transmission line was, he said.
Only after the San Bruno disaster, Haag said, did he realize that “there was a need to know” what lines were in the area, and that online maps and other resources were available to first responders.
He conceded that he should have known about the pipeline that exploded. “We didn’t have the information, we didn’t have maps of a pipeline going through,” Haag said. “I just didn’t know about it.”
Haag said he wouldn’t have fought the fire differently even if he had known about the pipeline. Firefighters’ major problem, he said, was that PG&E was unable to shut off the gas flowing to the rupture for an hour and 20 minutes.
“Without the fuel supply, there is a possibility we could have been in an offensive rather than a defensive mode,” Haag said.
Hard to come by
The chief added that PG&E had not gone out of its way to make sure city officials knew the gas transmission line was there. He said the company had not offered training for his department or access to PG&E’s computerized gas information database until after the explosion.
The pipeline itself was haphazardly marked, Haag said. Near where the blast happened at Earl Avenue and Glenview Drive, he said, firefighters found “plastic stickers” indicating the pipeline’s course.
“Some were there, some were missing, some were hard to identify,” Haag said.
Aaron Rezendez, PG&E’s safety program manager, said the utility distributes literature and videos about its system to fire departments and meets annually with officials in the San Bruno area. The company says its representatives review maps of gas-transmission lines during such meetings and provide links to the National Pipeline Mapping System.
Rezendez said firefighters and other officials can access a secure section of PG&E’s website to find the specific locations of pipelines. He said the utility is working to develop training exercises with firefighters and emergency crews in the wake of the San Bruno disaster.
PG&E said it also tries to educate residents about gas pipelines, but those efforts came in for criticism at the hearing. Deborah Hersman, chairwoman of the National Transportation Safety Board, pointed to a 2010 PG&E survey in which 15,000 people were sent an evaluation card about pipeline safety information – and only 20 people responded.
“You’ve got a serious problem,” she told Rezendez.
Rezendez said the response rate was “unacceptable to us” and had prompted the utility to ask, “What are we doing wrong?”
Bill inserts
PG&E uses bill inserts to notify people living near lines about safety measures they can take. Carl Weimer, head of the nonprofit advocacy group the Pipeline Safety Trust, said most such mailings are commonly prefaced by messages promoting the benefits of natural gas pipelines.
That does nothing to make recipients focus on recommended safety measures that follow, he said.
“We know that people in the communities have no idea that there are pipelines running through their neighborhoods,” Weimer said. “We really need to target the message better.”
‘Junk mail’
After the hearing, Hersman said federal officials “believe the pipeline industry can do a better job” of informing the public, as required under a 5-year-old law for pipeline operators.
Rep. Jackie Speier, D-Hillsborough, said sending safety alerts as bill inserts that resemble “junk mail” is unacceptable and an “abject failure.”
People who live near gas-transmission lines should be told as much in a specific mailing, said Speier, whose district includes the San Bruno neighborhood devastated in the blast. She is sponsoring a bill to require such notice for people living within 2,000 feet of a pipeline.
San Bruno blast: Feds seeking PG&E reforms
By Jaxon Van Derbeken
San Francisco Chronicle
March 2, 2011
Federal pipeline safety officials announced Tuesday that they will take a leading role in determining how Pacific Gas and Electric Co. should improve its gas pipeline safety practices in the wake of the deadly San Bruno explosion.
The California Public Utilities Commission, which critics have accused of laxness in enforcing pipeline safety laws in the state, will continue to be involved both in the investigation into what caused the Sept. 9 blast and a review of how PG&E can make its 5,700-mile gas-transmission system safer, officials said.
But the federal government, which traditionally leaves enforcement of U.S. pipeline laws to state agencies, will have a large say into whatever overhauls are imposed on the San Francisco-based utility.
The U.S. Pipeline and Hazardous Materials Safety Administration is “sending its top pipeline engineers, technical experts and inspectors to work with California (regulators) to evaluate PG&E,” the agency’s administrator, Cynthia Quarterman, said in a statement.
The federal experts will “thoroughly scrutinize PG&E’s plans” and “dig deep” into its practices of determining the risks to its pipelines, Quarterman said.
“This joint inspection is critical to the safety of millions of people served by one of the largest natural gas pipeline systems in California,” Quarterman said.
Grilled at hearing
PG&E’s practices were under intense scrutiny Tuesday during the first of three days of hearings convened by the National Transportation Safety Board into the San Bruno disaster, which killed eight people and destroyed 38 homes. Today, officials at the Washington hearing plan to focus on the state Public Utilities Commission’s regulatory regimen.
Officials for the state commission did not respond Tuesday night to requests for comment.
Paul Moreno, a spokesman for PG&E, said, “As we have said all along, we have been 100 percent committed to fully cooperating with investigative agencies and our regulators.”
As the hearings got under way, government safety officials quizzed PG&E managers about everything from how they determined safe pressure levels for pipelines to why the company had failed to install automatic or remote-controlled gas shutoff valves on the San Bruno line.
Gas kept flowing
Gas continued to flow to the point of the rupture for almost an hour and a half as PG&E workers drove to valves and manually cranked them shut. A PG&E dispatch center initially sent a gas-services representative to the site who didn’t know how to shut off the valves, investigative documents showed.
San Bruno fire officials have said the continued gas flow worsened the damage from the explosion.
Matt Nicholson, a pipeline investigator with the federal safety board, asked PG&E engineer Chih-Hung Lee Sr. about an internal policy memo that he wrote in 2006 that downplayed the importance of valves that close automatically or by remote control.
Such valves, Lee wrote, have “little or no effect in on increasing human safety or protecting properties.”
Nicholson pointed to a 1999 Transportation Department study that found that automatic shutoff valves could be useful in the event of a pipeline rupture. Failing to shut off a gas flow means “any fire would be of greater intensity and would have greater potential for damaging surrounding infrastructure,” the report said.
Resisting shutoff valves
PG&E responded at the time that it would consider such valves where feasible. But in an interview in January with investigators looking into the blast, the head of the company’s integrity management program, Sara Peralta, said PG&E still agreed with the conclusion that automatic shutoff valves provided no safety benefits.
Peralta told the panel Tuesday that she was not with the company when Lee made the original conclusion in 2006 but backed his findings.
Lee testified that in minimizing the importance of automatic valves, he had relied not on the Transportation Department report but on industry studies that found that most damage from a rupture would take place within 30 seconds.
PG&E officials conceded that automatic shutoff valves would have cut the flow of gas to the San Bruno rupture within less than 15 minutes.
Rep. Jackie Speier, D-Hillsborough, whose district includes the devastated neighborhood, said relying solely on industry studies was “preposterous.”
“It’s frightening to me to think that’s the kind of analysis that PG&E would engage in when making an assessment on safety,” Speier said.
Push for changes
Speier is among the lawmakers on the federal and state levels who have introduced legislation that would force PG&E to increase the number of automatic shutoff valves. The company says it has embarked on a program to add hundreds of the valves to its system by 2020.
But Edward Salas, PG&E senior vice president for engineering and operations, testified that automatic or remote-controlled shutoff valves have problems of their own. When they are activated, he said, gas pilot lights can be shut off in thousands of homes, which could take the utility months to relight.
Also, any gas remaining in the pipeline can back up into people’s houses, creating additional hazards, Salas said.
Another issue that arose at Tuesday’s hearing was PG&E’s practice of intentionally surging gas pressure on some transmission lines. The utility said it did so to maintain higher legal caps so it could be sure of delivering all the gas it needed to, but some critics have called it an unsafe practice that caused stress on pipes.
Intentional pressure surges
PG&E intentionally surged pressure twice on the San Bruno line to just above the legal maximum, in 2003 and 2008. Peralta testified that “planned increases were not a cause of concern” and called them “routine.”
In a response to investigators’ queries about the practice in December, PG&E said one reason for the intentional surges was to avoid a situation where an accidental spike would break a pipeline’s legal limit. That would initiate a federal requirement that PG&E shut down the line to conduct expensive and time-consuming inspections for damage.
“To avoid this and any potential customer curtailment that may result, PG&E has operated … some of its pipelines that would be difficult to take out of service at the maximum pressure” level, the utility said.
“It was a choice we made,” Peralta said Tuesday. “I wouldn’t say it was in avoidance of anything.”
San Bruno pipe probably pieced together from scrap
By Eric Nalder
San Francisco Chronicle
March 1, 2011
The section of 1950s gas-transmission line that exploded in San Bruno was probably pieced together from scraps of pipe left over from other Pacific Gas and Electric Co. projects, the company told federal investigators.
Documents released Tuesday also revealed that it was a misinterpretation of old records – not just a lack of documents – that led PG&E to classify the doomed pipe incorrectly as seamless, meaning that it had been manufactured without a seam weld.
In fact, the explosion Sept. 9 that killed eight people and destroyed 38 homes began at a defective seam weld, according to a preliminary National Transportation Safety Board metallurgy report.
PG&E didn’t know the pipe had such welds, and the company never conducted an inspection that could find faulty ones.
Blast mysteries
How such a badly welded pipe was buried in the ground in San Bruno in 1956, at a time when PG&E crews were relocating a 1948-vintage pipeline to accommodate a new neighborhood, is part of the mystery unfolding as the federal safety board holds three days of hearings this week in Washington.
Experts who have reviewed the federal metallurgy report have questioned why the San Bruno pipe was made with an unusual number of short pieces, known as pups, which were joined together. There were six pups on the line.
Pups are sometimes pieces of good pipe salvaged from longer sections of pipe that failed pressure tests at the factory, Edward Salas, PG&E vice president of engineering and operations, testified Tuesday.
One veteran metallurgist in the hearing room audience said the pups Salas described aren’t safe.
“As a practice, I think any (pipe section) that fails a (pressure) test should be scrapped altogether,” Doug Chisholm, a Virginia consultant with 30 years’ experience in the pipeline industry, said in an interview.
Pipe was running low
The company’s stock of 30-inch transmission pipe “was getting low” when the San Bruno relocation project occurred in 1956, PG&E told the federal safety board in answers to written questions.
“Surplus pipe and potentially salvaged pipe from several previous pipe purchases were likely used on the 1956 construction,” the company said.
The company said the surplus pipe may have been stored in the back of a storage yard in Oakland. PG&E couched its written responses with terms such as “we believe” because the company is still researching records.
Bad records entry
Another mystery being addressed in this week’s hearings is why PG&E’s computerized records showed that the transmission pipe was seamless.
Seamless 30-inch pipe wasn’t manufactured back then, records show. When PG&E inspected the pipe in 2009, it used a technique ill-suited for discovering faulty seam welds.
The mistake was made in 1998, according to transcripts of interviews with PG&E officials and records, and remained in the company’s computer system despite a fact-checking process designed to eliminate such errors.
The problem was that someone made an entry into PG&E’s all-important computerized database that said the San Bruno pipe was seamless. It appears the error was a misinterpretation of the letters “sml,” which had been noted on a paper record known as a journal voucher.
Such vouchers are “created by the accounting department to reflect the transfer of materials from one project to another,” the company told federal investigators.
Journal vouchers are not meant to be pipeline specification records, PG&E said.
It was fixable
Had the company checked its original engineering records, it would have linked the coded description of the pipe on the journal voucher to a “material code description table,” which would have indicated the pipe was manufactured with a seam weld, Robert Fassett, PG&E director of integrity management and technical services, told investigators in January.
“If someone had actually taken that document, looked up that material code, they would then have said this is a (welded) pipe,” Fassett said.
A Chronicle investigation published in February revealed that PG&E didn’t properly oversee computerized data entry in the mid-1990s.
Other undamaged pipe near the blast site on the San Bruno pipeline was also mislabeled as seamless in the database, Brian Daubin, a PG&E engineer involved with system, told federal investigators in January.
“The company knows it must improve its system of records,” PG&E said in a statement Tuesday, adding that the company has 300 employees and contractors “hard at work confirming the quality of its data.”