Big explosion near San Francisco Airport

usa breaking news/twitter ^ | Sept 9, 2010

[calcowgirl]

Oh, no... I had no idea when I posted the excerpt that it was the family of one of our freepers.
He posted on this thread last night. How terribly sad and tragic.
Thank you for the link.

[abigailsmybaby]

Thanks for the info. PG&E’s gonna get hit with sooooo many lawsuits. The last time an incident of this nature happened they shut down all construction in order to pay the lawsuits.

[chilltherats]

Best news I’ve heard all day. Thank God.

[chilltherats]

It may well be PG&E’s fault, but we don’t know that for a fact yet. Why don’t you just back off for now?

[BigSkyDream]

The Obama administration -ie- AG Holder is sending teams of lawyers to the area while Sec. Salazar is declaring a moratorium on all natural gas pipelines until they understand the cause while the President plays a round of golf on his current vacation.

(Gulf oil spill sarcasm off)

[jetson]

It was probably the microbe that weakened the pipe that they find in all of the pipelines. Lives off of petroleum and does not need oxygen. The same stuff that ate the oil at sea in the gulf. Kind of spooky running huge pipe lines right through a neighborhood.

[yesca]

..esp. only 3 feet underground (that's from a report I heard, hard to believe).

When home shopping in the future I recommend asking about pipeline locations.

[PA Engineer]

It was probably the microbe that weakened the pipe that they find in all of the pipelines. Lives off of petroleum and does not need oxygen. The same stuff that ate the oil at sea in the gulf. Kind of spooky running huge pipe lines right through a neighborhood.

My understanding is the pipeline is 60 years old. It is possible the pipeline was present before the neighborhood development. Sulfate reducing bacterial corrosion is not that common. When present it can be overcome with proper corrosion engineering practices.

I agree with other astute freepers who saw the road cut at the sewer pipeline crossing and raised the potential for third party damage. To get to the deeper sewer line they had to expose the transmission pipeline. This work was done during the past two years.

Three foot depth of burial for pipelines is common. Building a development around it is a local zoning issue if the ROW is not owned by the pipeline company.

I hope that helps clarify a few issues.

[jetson]

Sulfate reducing bacterial corrosion is not that common. When present it can be overcome with proper corrosion engineering practices.

I heard that the process you are refering to is not reliable especially if moisture is present.. Pig scanning with section replacement is the best bet.

[roadcat]

In the aftermath of the tragedy, lots of folks are stepping forward to help. Goes to show you that basically, Americans are very giving and compassionate.

Lots of people donating blood, clothes, food, money, etc. One of my daughters works at Genentech here in South SF. 12 of their employees lived in that neighborhhood and lost their homes or had them severely damaged, 1 employee is unaccounted for. As I hear it, the company is housing them for free for several months at a local Marriot and taking care of all their needs. So local companies are also stepping forward to help. The USA is the great, isn't she?

[PA Engineer]

I heard that the process you are refering to is not reliable especially if moisture is present

If you have a link, I would like to read it. I have been doing "corrosion failure" investigations for 28 years (professionally), and am always willing to look at contrary evidence. Please provide a link. External corrosion is only possible when an electrolyte is present. Pig scanning is contraindicated when there is damaged related pitting. "Pig" ultrasound will provide an average wall thickness and may be useful for general pitting or failures related to coating holidays.

[jetson]

If you have a link, I would like to read it

Only stuff I have read waiting for a haircut and listening to radio programs. Believe me I'm all ears at what you are saying.

[Martinish]

Has anyone considered the fact that this entire neighborhood was built on the San Andreas Fault. And then the city planners placed a large natural gas line under the community. And now the gas line has exploded. What is considered a safe distance from a slip strike fault for such a large gas main?

[roadcat]

I don't know. Lots of stuff is built on the San Andreas Fault here. Back in 1971 I graduated from Skyline College a few blocks from the fire area. It was built right on the fault. Sits right on a mountain top with beautiful views of the Pacific Ocean and of San Francisco Bay. There were still lots of open space surrounding the college at that time. Since then they've built lots of new subdivisions in the canyons surrounding the college. As for the fire area, the gasline was there in open space before the homes were built.

I went to
https://www.npms.phmsa.dot.gov/
To see if any major gaslines were next to my home. No, but one runs in streets right in front of our BART subway station, high school, a major city park that's always crowded and other busy structures. These things are everywhere in residential neighborhoods.

[roadcat]

You guys are amazing. You were speculating about sewer work being done a couple years before, as probably weakening the gas pipeline. And reporting this the same time as the fire raged.

Local news now reporting that records surfaced Saturday showing that San Bruno City Council hired a construction company to replace underground sewer lines near the gasline. 1650 feet of aging sewer pipes on Earl Avenue from Sneath Lane to Glenview Drive.

To avoid digging trenches, they used "pipe bursting", something you guys mentioned but I never heard of before. They dug holes here and there, pulled a large cone-shaped device through the old sewer pipe, shattering them, while pulling a new polyethylene sewer pipe in behind them. The technique causes ground shaking and disruption of adjacent soil and rock. So authorities are looking at this as a possible cause of the weakening of the gas line.

Good investigative work, guys!

[jetson]

I heard that the process you are refering to is not reliable especially if moisture is present If you have a link, I would like to read it. I have been doing "corrosion failure" investigations for 28 years (professionally), and am always willing to look at contrary evidence. Please provide a link. External corrosion is only possible when an electrolyte is present. Pig scanning is contraindicated when there is damaged related pitting. "Pig" ultrasound will provide an average wall thickness and may be useful for general pitting or failures

Hmmm...seems that bacteria may have been the culprit.

[PA Engineer]

Hmmm...seems that bacteria may have been the culprit.

Please tell me more. Thanks.

[jetson]

http://www.tradeslive.com/2010/09/27/san-bruno-blast-microbial-culprit-considered/