For the people who lived in San Bruno’s Crestmoor neighborhood, the explosion came as suddenly as an ambush. One moment, they were making dinner, flipping on their TVs to watch a football game, tidying their homes. The next, their dinners, their TVs, their homes were on fire, and they were running for their lives.
But the explosion of the San Bruno transmission pipeline was no case of spontaneous combustion. Over the last year, federal investigators have carefully pieced together its precursors, a series of bad decisions and organizational failures over the course of decades by PG&E.
The company had numerous opportunities to avert the deadly explosion, but over and over, it failed to do so. This “litany of failures,” as it was described by leaders of the National Transportation and Safety Board in a hearing last week, resulted in eight people dead and 38 homes destroyed.
It wasn’t the first time something like this had happened. PG&E pipelines failed elsewhere in 1980, and again in 2008, each time killing someone. Investigations of those disasters were followed by recommendations for vast safety improvements — but these recommendations were neither adequately heeded by PG&E nor enforced by state regulators, NTSB investigators found.
PG&E’s leaders have promised that this time will be different, and indeed, the impact of the San Bruno disaster has been much larger than its predecessors: It has sparked multiple investigations, criminal probes, dozens of lawsuits, legislation, and a national conversation among lawmakers and regulators about how to make the aging system of pipes throughout the country safer.
NTSB chairwoman Deborah Hersman said it was “imperative” that the country learn from PG&E’s mistakes, and that people wake up to the dangers under their feet.
“Because pipelines are usually underground, most people don’t even know they exist, much less where they are located,” she said. “Recently we’re seeing a flurry of activity on several fronts to make improvements to better ensure pipeline safety. This is good. But the proof will be in the pudding.”
The tale of the San Bruno disaster goes back more than 50 years to the summer of 1956. A PG&E crew was relocating an 1,800-foot chunk of the gas pipeline — known as Line 132 — that the company just laid eight years earlier, to accommodate the neighborhood that was about to grow on top of it.
At the bottom of a small ravine, the crew welded together a half-dozen small chunks of pipeline, or “pups,” perhaps to help the pipe conform to the contour of the landscape. Had inspectors looked closely, they would have been alarmed: The pipe was cracked.
The cracked pipe was so weak it would have failed a strength test, but PG&E never conducted one. Instead, over the coming decades, PG&E instead chose to implement a cheaper pipeline-maintenance program that could not detect cracks. Even after other problematic seams and leaks were discovered elsewhere on the line, PG&E decided against testing or inspecting it. Hersman described this strategy as an “integrity management program without integrity.”
The next failure by PG&E was to forget everything it ever knew about the pipe. In the mid-1990s, a data-entry error resulted in Line 132 being labeled as “seamless” — though no such pipe was manufactured in 1956. To the immense frustration of investigators and regulators, PG&E has not been able to provide documentation about where the six pups came from, or whether there may be other places where such pipes exist.
The day of the explosion, disaster might still have been prevented — or at least postponed. A PG&E crew working in the Milpitas station accidentally cut off the power supply to the valve that controlled the pressure in the pipeline that ran under San Bruno — a contingency the crew should have foreseen and avoided, investigators said. Pressure began to rise on the pipeline, and when the crack in Line 132 suddenly became a fissure, pressurized gas exploded out of it and created a firestorm.
Because the company had no emergency response plan adequate to handle the disaster, it allowed gas to fuel the fire for 95 minutes before an off-duty PG&E crew finally took charge, shut off the gas and halted the flames.
At the hearing last week in Washington, D.C., NTSB member Robert Sumwalt said he was “baffled” as to how “one of the biggest natural-gas providers in the country winds up with organizational deficiencies like this.”
For Tammy Zapata, a survivor of the accident, the failures are unforgivable.
“I have absolutely no respect for PG&E. … It was so preventable,” she said.
PG&E Senior Vice President Greg Pruett said he is not surprised that the company has received such harsh criticism.
But he noted that PG&E has already begun making drastic changes to its pipeline safety program, and that it hopes to become the country’s safest pipeline operator. The company plans to take NTSB’s recommendations seriously, he said.
“Their words fell on very receptive ears,” he said.
Source: PG&E regulatory filing