Saturday, September 11, 2010

Will The Crestmoor Natural Gas Explosion And Fire In San Bruno, California Impact The Proposed Alaska Natural Gas Pipeline?

Many Alaskans are frustrated over the slow progress towards a natural gas pipeline in Alaska. However, the delay may permit us to learn some lessons on what can happen when a catastrophic event takes place -- and factor those lessons learned into the plan in advance. The catastrophic explosion of a main natural gas distribution line and subsequent explosion, which killed four people and injured 52 at last count, leveled 37 homes and structurally damaged eight others in a San Bruno, California neighborhood, may offer some lessons learned. And such lessons are needed -- BP in particular has been plagued by accidents and spills up on the North Slope. Natural gas is much more volatile -- and much less forgiving of mistakes -- than oil.

For those who want more information on the San Bruno disaster, here are some of the most useful links (the San Jose Mercury-News offers the best content so far):

-- Map of neighborhood available HERE.
-- A better map of the neighborhood HERE.
-- List of destroyed/damaged homes HERE.
-- Excellent San Jose Mercury-News gallery of 46 photos HERE; numerous high-resolution aerial shots.
-- San Francisco Chronicle gallery of 54 photos HERE.
-- San Jose Mercury-News gallery of 15 photos HERE, some showing area shots illustrating the scope of the disaster.
-- Another San Jose Mercury-News gallery of 19 photos HERE, mostly showing recovery efforts.
-- Link to all related Mercury-News content HERE.

Here's an amateur video shot by a resident inside a home near ground zero at the moment of the initial explosion:

Here's another video showing an aerial shot of the neighborhood while the fire was in progress.

Here's a summation of what happened, based on analysis of numerous media stories. On Thursday September 9th, 2010, at approximately 6:15 PDT, a main 30-inch natural gas distribution line exploded in the Crestmoor Canyon neighborhood of San Bruno. Because Pacific Gas & Electric (PG&E) could not completely shut off the gas supply to the line for at least 30 minutes, natural gas continued to produce fireballs, some of which shot up to 1,000 feet into the air. The combination of intense heat, embers and ashes spread by strong winds, and smaller neighborhood and residential gas lines overheating and exploding caused the fire to jump from one house to another until ultimately 37 were destroyed. In addition, even after PG&E turned off the natural gas supply, additional time was required for the remaining natural gas in the system to purge. So it is estimated that natural gas fueled the fire for a total of at least one hour after the initial explosion. The blast left a crater 40 feet long, 50 feet wide, and an estimated 15 feet deep at "ground zero". NOTE THAT THIS IS PRELIMINARY INFORMATION ONLY and that a detailed investigation could last for a couple of months.

Albany Fire Chief Marc McGinn further explained the complexity of dealing with a natural gas fire. "In something that big, you can't put the gas out...If it's a small line, like from a house, you might cap it. But a house line has maybe half a pound of psi (pounds per square inch) coming through it - in a street line, it's more like 200 psi...You have to put a natural gas fire out at the source by shutting off its fuel. You might be able to extinguish the flames without doing that, but the gas will still be venting and can catch on fire again when it encounters something that ignites it," McGinn said.

PG&E says that the pipe was a 30-inch carbon steel transmission pipe with a .375-inch wall thickness, originally installed in 1956, before the invention of "smart pig" technology which permits a pipeline inspection gauge of up to 15 feet long to pass through the line and detect anomalies. It has not yet been revealed how frequently this line has been inspected since the installation; Federal law requires transmission lines to be inspected every seven years. The company operates 48,580 miles of natural gas pipelines, many located close to earthquake fault lines and passing under neighborhoods where residents may have no idea of the pipes' existence. Reports are now filtering out that some residents smelled natural gas at least a week before the explosion, and possibly as long as three weeks beforehand. Some reportedly called PG&E; the company sent representatives to investigate, but could not find enough confirmation. One resident, Tim Gutierrez, related his experience: "PG&E came out...I was working in my garage and they told me to shut the door, shut the garage, go inside, that there was really heavy, strong gases. After being in the neighborhood for a little bit, they packed up and left."

The Mercury-News also reports that PG&E has cut some corners in the past, not necessarily out of malevolence, but out of sheer negligence and lack of vigilance. In May 2008, the California Public Utilities Commission, which oversees natural gas pipelines, found in an audit that PG&E had not properly trained its field representatives on the use of gas-detection equipment and grading leaks outdoors. And in May 2010, a consumer group disclosed internal PG&E documents that revealed shortcomings in the way the company inspected its gas-distribution lines from 2004 to 2007.

PG&E has expressed its condolences to the victims and has said that if it is ultimately determined that they were responsible for the cause of the incident, they will take accountability. They've already set aside $1 million for community groups such as the Red Cross, the United Way, and others involved in helping residents of the stricken area. In a filing with the Securities and Exchange Commission on Friday, PG&E reported it has $992 million in fire insurance. But the main questions left to be answered:

(1). How many calls it received from neighbors reporting a potential gas leak before the explosion?

(2). What repair work, if any, its crews performed before the explosion, and when?

(3). When the pipeline, which was built in 1956, was most recently inspected?

While an Alaska natural gas pipeline will pass mostly through unpopulated areas, it's obvious that strict inspection protocols will have to be developed and enforced to minimize the occurrence of a similar disaster here. And enforcement is equally important -- BP's record shows that while protocols were in place, their own enforcement mechanism was weak.

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