Crime & Safety

America's Vast Fuel Pipeline Network: How Dangerous Is It For Communities Like San Bruno and Walnut Creek?

Deadly gas pipeline explosions in Walnut Creek in 2004 and now in San Bruno raise questions about how safe pipelines are, especially those that run near homes, schools and downtowns.

Nearly half a million miles of oil and gas transmission pipeline crisscross the United States. They carry volatile or flammable materials and alternately run through remote and densely populated regions--including through residential neighborhoods and near suburban downtowns.

This is certainly the case in two Bay Area towns--Walnut Creek and San Bruno--that have been rocked by deadly gas pipeline explosions in the past six years. 

At least four people are now confirmed dead in Thurday evening's explosion and fire in San Bruno, which erupted from a punctured natural gas pipeline. More than 50 people have been injured, and an entire neighborhood has been devastated.  

Find out what's happening in San Brunowith free, real-time updates from Patch.

That kind of hazardous incident, so close to where people live is sadly familiar to Walnut Creek residents. In 2004, a backhoe operator helping to install a water main along South Broadway breached a high-pressure gas pipeline. The backhoe operator and crew were working along a stretch of South Broadway a half mile from downtown, across the street from Las Lomas High School and adjacent to a residential neighborhood. The breach ignited a fireball that killed five construction workers and injured four others; it also badly damaged one nearby home.

There are roughly 180,000 miles of oil pipeline in the United States carrying more than 75 percent of the nation's crude oil and around 60 percent of its refined petroleum, according to a 2004 congressional report, Pipeline Security: An overview of Federal Activities and Current Policy Issues. (PDF attached). The U.S. natural gas pipeline network consists of around 210,000 miles of interstate transmission, plus approximately 75,000 miles of intrastate transmission.

Find out what's happening in San Brunowith free, real-time updates from Patch.

Despite this "staggering web of explosive gas wrapped up tightly in metal pipes," catastrophes like the ones  in Walnut Creek and now in San Bruno "are surprisingly few and far between." So says a report published Friday by MarketWatch. 

Quoting U.S. Department of Transportation figures, Marketwatch said that over the past two decades, there have been 846 "significant" accidents from onshore gas transmission, resulting in 33 fatalities, 173 injuries and $757 million in property damage. "That comes to an average of 42 accidents per year dating back to 1990, with two deaths, nine injures and almost $38 million in damage."

The transportation department defines significant accidents as incidents involving a fatality or serious injury or at least $50,000 in damage in 1984 dollars, MarketWatch says.

Similarly, the congressional report contends:

"Taken as a whole, releases from pipelines cause relatively few annual fatalities. Oil pipelines reported an average of 1.4 deaths per year from 1997-2001. Gas pipelines reported an average of 18.6 deaths per year during the same period."

The most common causes of "pipeline releases" include third-party excavation, corrosion, mechanical failure, control system failure and operator error, the congressional report says. Natural forces, such as floods and earthquakes, can also damage pipelines.

The explosion that rocked San Bruno's neighborhood of single-family homes was caused by the rupture of a 30-inch Pacific Gas and Electric Co. natural gas pipeline.

The National Transportation Safety Board will join local officials in determining the cause of the rupture. PG&E has acknowledged that a company gas transmission line was ruptured prior to Thursday night's explosion. Some residents told reporters they had smelled gas in the neighborhood and had seen PG&E trucks in the area in the days before the explosion.

In the 2004 Walnut Creek explosion, a Houston-based energy company was found, under a 2007 criminal plea agreement, to be the "proximate cause of the puncture of the line and of the deaths and injuries that resulted," the San Francisco Chronicle reported. Kinder Morgan, the nation's largest underground fuel shipper, had failed to properly mark a bend in its Walnut Creek pipeline near where the crew was working on the water main. 

The families of those killed and injured by the blast also reached separate civil settlements totaling at least $69 million with Kinder Morgan and other companies that were involved in the incident, including the Livermore contractor doing the water main installation for the East Bay Municipal Utility District.


Get more local news delivered straight to your inbox. Sign up for free Patch newsletters and alerts.

We’ve removed the ability to reply as we work to make improvements. Learn more here

To request removal of your name from an arrest report, submit these required items to arrestreports@patch.com.