SAN BRUNO VICTIMS AND THEIR FAMILIES DESERVE LONG-OVERDUE ACTION

September 9, 2020

By Member Jennifer Homendy, National Transportation Safety Board (NTSB) Safety Compass

Today marks 10 years since the devastating natural gas pipeline rupture that shattered a residential neighborhood in San Bruno, California. The September 9, 2010, explosion destroyed 38 homes and damaged 70 others. Even worse, 8 people were killed, 10 people sustained serious injuries, and many others suffered minor injuries.

The Accident

When I think of San Bruno, I struggle with the ‘right’ words to describe the horrific events that unfolded shortly after 6:00 p.m.—a time when many families across our nation are just sitting down for dinner.

In the moments after the rupture, calls flooded into 911, with reports of what many thought was a plane crash, a gas station explosion, or some combination of the two. One caller said it felt like an earthquake, and a fire captain who was on scene said, “It looked like Armageddon.” In fact, the rupture was so explosive that it produced a crater about 72 feet long by 26 feet wide and launched a 28-foot section of failed pipe about 100 feet south of the crater. The released gas almost immediately ignited. Emergency responders arrived within minutes to battle the ensuing inferno, yet it took Pacific Gas & Electric (PG&E) an astonishing 95 minutes to shut off the flow of gas that was intensifying the destruction. Firefighting efforts continued for 2 days, with 600 firefighters and 325 law enforcement personnel on scene.  

San Bruno, CA, accident scene with the crater in the foreground and the ruptured pipe section in the background
San Bruno, CA, accident scene with the crater in the foreground and the ruptured pipe section in the background

NTSB Warnings

I’m not going to get into the numerous failures at PG&E that led to the rupture. I want to focus on those 95 minutes. In December 1970, the NTSB released a Special Study of Effects of Delay in Shutting Down Failed Pipeline Systems and Methods of Providing Rapid Shutdown. You read that right—1970. We found that delays in shutting down pipelines increase the magnitude of catastrophe, and that, when the flow of gas or hazardous liquid is stopped soon after an initial rupture, the effects of many accidents would have been minimized or eliminated. In other words, numerous lives could’ve been saved, and injuries prevented.

Our report highlighted the 1968 rupture of a medium-pressure gas line in front of a daycare in Hapeville, Georgia. Construction crews on scene were unable to locate the buried valve to shut off the gas flow. A few minutes later, an explosion occurred inside the daycare. The ensuing fire engulfed the building and nine people were killed, including seven children. Three other children were seriously injured.

Nine other incidents—all involving failures to shut down pipelines—were cited in the report, and many more have occurred since it was published. The common theme? What we said in 1970 held true in San Bruno and holds true today: “For every one of the accidents cited, there are devices or equipment currently available which probably could have prevented the accident or greatly minimized its effect.”

We’ve been urging federal regulators to require those devices for 50 years! In fact, they’re still on our Most Wanted List of transportation safety improvements.

The San Bruno Investigation

Getting back to San Bruno. In those crucial 95 minutes during which the gas continued to flow, PG&E control center staff knew there had been a rupture along the pipeline, but never once called 911. The three PG&E employees who first arrived on scene, two of whom were supervisors, had no idea how to operate mainline valves. They had to call people who were qualified to operate them, and by the time those mechanics located the valves and got to the first one, it was 7:20 p.m., over an hour after the rupture occurred. Meanwhile, the fire, described by NTSB investigators as a massive blowtorch, was still raging.

Because gas was being supplied to the break from both the north and the south, the shutoff valves closest to the break had to be closed to shut down and isolate the rupture. The shutoff valves were located about 1.5 miles apart, on either end of the break, and they had to be shut manually. Had PG&E installed readily available technology—valves with remote closure capability or ones that would automatically shut off the gas flow in response to pressure changes in the line—the amount of time the fire burned, and thus, the severity of the accident, could’ve been significantly reduced. In fact, this technology could’ve stopped the flow of gas the moment the rupture was detected.

In our final report on the accident, we recommended that federal regulators—the Pipeline and Hazardous Materials Safety Administration (PHMSA)—require  pipeline companies to install automatic shutoff valves or remote shutoff valves in High Consequence Areas (defined as populated areas, drinking water sources, and unusually sensitive ecological areas).

PHMSA’s Response

On February 6, 2020, PHMSA published a notice of proposed rulemaking (NPRM), “Pipeline Safety: Valve Installation and Minimum Rupture Detection Standards,” claiming the NPRM responds to recommendations from the NTSB. It doesn’t. It requires automatic shutoff valves, remote-control valves, or equivalent technology to be installed only on newly constructed or entirely replaced onshore natural gas transmission and hazardous liquid pipelines that are larger than 6 inches in diameter.

Remember the daycare accident I mentioned? The pipeline that ruptured in that tragedy was only 1 inch in diameter. Existing gas transmission lines (like the PG&E line that ruptured in San Bruno), newly constructed or entirely replaced lines that are less than 6 inches in diameter, gas distribution systems, and offshore transmission lines are completely excluded from the NPRM’s requirements.

In other words, PHMSA’s solution won’t prevent another San Bruno disaster. Given that there are 2.6 million miles of gas pipelines in the United States, most of which date back to the 1950s and the NPRM doesn’t address any of them. With those numbers, another tragic accident is destined to occur, and if I’m the member on scene—or even if I’m not—I’ll remind PHMSA and industry, yet again, of all the ruptures we’ve investigated and all the opportunities they had to save lives.

To all those who lost loved ones in San Bruno or in another pipeline tragedy, you remain in our hearts. We are still fighting for you.

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