Four confirmed dead in San Bruno explosion... *Disregard the plane crash speculation [ame="http://www.youtube.com/watch?v=P--2xdwSm44&feature=related"]YouTube - San Bruno Explosion, September 9, 2010, 6:38PM[/ame] More terrible news.
Question for the municipal gas engineers on the board is why it took several hours for PG&E to finally shut off the supply. Since the breach was feeding a firestorm wouldn't it have made sense to cutoff immediately every valve on their system that could have fed that line, even if it meant shutting off supply to all the adjoining towns? In an emergency we don't all think clearly, so I can understand a certain amout of delay (such as determining that the cause was in fact a gas line breach and not a plane crash), but several hours seems more than ample time to get past initial shock and start to take calculated if drastic steps to abate the gas flow. So there might be some technical reason it took so long. It's unsettling to consider that we're all sitting on potential bombs like this: fuel lines underground that could breach in unexpected and disastrous ways. It'll be of keen interest why this breach happened.
Horrible situation for all involved. That said, I get a very odd feeling about this... I don't think we've heard the end of why it happened.
I grew up in San Bruno. I now live two towns over (in Burlingame). I saw the fire as it was burning from Rollins Road near the Millbrae BART station. I don't know how to describe it another than a huge fountain of fire and smoke. I was miles away but I could see the main gas-fed fireball clearly just standing on the street. It's a horrible, tragic situation. My heart goes out to the families of those who lost loved ones, those injured and to everyone who lost their home. Honestly, given the location of the gas line rupture, it's amazing more people weren't killed.
A number of years ago, a over-pressure situation in the gas mains destroyed an entire city block in one of the neighboring small towns. The gas regulators on all of the buildings were overwhelmed by the high pressure, and in turn allowed high pressure gas into the buildings. Predictably, the result was explosions and fires. Tom
It does seem like that for something as critical as a 24 to 30 inch gas high pressure main going a highly populated area, that pressure and flow should be well enough monitored at appropriate distances that a lot of alarms and red lights would be going off on a control panel someplace at PGE.
Apparently, there were complaints about gas leaks before the explosion: Utility in gas blast 'looking into' odor complaints - U.S. news - msnbc.com And, steel gas lines seem to be having problems nation-wide: Steel gas mains draw regulators It kind of sucks that people have to die before actions get taken. Couldn't companies be just a wee bit proactive for a change?
I recall a seriously bad gas line explosion in a suburb of the Twin Cities, MN, oh, probably about 15 years ago. The pipeline company was known for being substandard. Just remembering, that's all.
Not sure what a "municipal gas engineer" is, but I'll take a shot at your questions First of all, one will not find shutoff valves every 10ft. For a MP or HP pipeline, more like every few miles, sometimes every 20-50 miles or at every compressor station Second, there is an enormous amount of pressure AND volume in those lines. No doubt valves upstream and downstream were closed almost immediately, it took that long for the residue pressure and product to bleed down Third, steel pipelines are cheap, but long-term their performance is undesirable. Soil conditions can cause severe corrosion problems, that can result in perforation. Some soil conditions cause galvanic errosion. Depending on where the pipeline is located, and whether it runs East-West or North-South, one can expect Geomagnetic Induced Current flow. This is a cause for concern in Scandinavian countries and the Siberian region of Russia Since natural gas has methyl mercaptan, a thiol, added as an identifying agent (Actual methane is generally odorless), any complaints about natural gas odor in the area before the explosion generally indicates not just a small perforation, but major perforations all along that stretch of pipeline There was another pipeline, this one for petroleum (Gasoline, diesel, jet fuel, etc) owned by Calnev, that was damaged by a runaway train in San Bernardino. Around 2 weeks after the derailment the pipeline ruptured Bad thing about pipelines is that they are out of sight, and out of mind, until something goes wrong. This applies to natural gas, petroleum, drinking water, sewage, etc. Nobody cares until somebody gets killed
What he said. The aging and deterioration of our underground infrastructure is a national problem that can only get worse. Here on the East Coast, older cities are experiencing accelerating rates of failures of water and sewer systems, essential underground utilities. Here in Ballamer, it is a costly situation, the water system alone needs $2.2 Billion for fixes and last year city water rates rose 9% to cover it. The system-wide leakage is 20%. In my neighborhood in NE Ballamer, it was developed around 1940, there have been 16 major leaks within 4 blocks of our home in the last 4 years. (Hint to home buyers: many patches in the roadway indicate chronic water/sewer system problems. Fresh blacktop along a block or two of street is a just a cosmetic coverup. ) The municipal sewer system is no better off. "The EPA and the DOJ are the plaintiffs, along with the Maryland Department of the Environment (MDE), in a Clean Water Act lawsuit in U.S. District Court filed against the city of Baltimore a decade ago over its illegally leaky sewer system. Five years ago, a "consent decree" was entered in the matter. Under the decree, the city must spend almost a billion dollars over 14 years, starting in late 2002, to get its sewer system into compliance with the federal Clean Water Act. So far, with less than a decade to go, the city has spent nearly $260 million and has repeatedly raised water-and-sewer rates to pay for it." Pardon Our Filth: City Sewage Keeps Flowing Into The Bay At the risk of politicizing this discussion, IMHO, all of this is the result of the gross misunderstanding of what constitutes the "Homeland Security" of our country and it's citizens. For the most part, our future security, health and happiness is dependent on what we do, how we spend or tax money, and what services we provide and maintain here at home, not out there or over the horizon.
Only for the small leaks. The big ones take out whole streets. I have noticed the replacement pipes around here seem to be huge plastic extrusions. Hopefully stuff that lasts a century instead of a few decades.
Partially agree. Since "out there" now consist of huge components of our light manufacturing, oil, debt, metal ores, etc. it cannot be ignored. That said, "our" future primarily involves both economic and environmental issues that no longer can be solved just by armed intervention.
AFAIK, a firm age has not been officially released yet. Some news sources have quoted PG&E as saying it was 40-50 years old, my wife heard on a local Bay Area program that it was installed in 1947 which would make it 63 years old. Edit: A PG&E spokesman, Andrew Souvall, has said that section of pipe was put there in 1956, so it's 54 years old.
More detail on the explosion Gas Pipeline Blast Kills Four, 50 Homes Destroyed | Chem.Info Just got this in my email inbox today
PG&E has put up $100 million toward the costs of the blast: PG&E creates $100 million fund for blast victims - U.S. news - Life - msnbc.com Depending on how many houses ultimately have to be re-built, the fund could grow.
And it happening around 6:15 pm, I don't know if you could have picked a worse time. All those people coming home from work. My brother's house (he sold about 8 years ago) was about 9 - 10 houses up Claremont from the explosion. (If you go to Apriusfan's MSNBC link, pict #10, and move to the intersection (right) from the explosion (there are two destroyed houses and an undestroyed PINK house, go up 10 houses from the Pink house (on Claremont) and his old house is there (off the photo)). No damage to his old house (or his neighbors) because the prevailing winds were blowing away from his house. In one of the overhead photos, you could see the burn patterns (houses) and tell exactly where the prevailing winds were blowing, where they shifted for a bit, and which houses were destroyed by the explosion. I grew up less than 1.5 miles from the site and know some of the people that got displaced. Awful thing to have happen.
Hopefully, they have the smarts to allocate about that much or more for inspecting, identifying, and replacing all the remaining sections that are not proven to be at full integrity.
It is not hopefully; it is isbe: State Orders Inspection of All Natural Gas Lines - Local News - San Francisco Bay Area, CA - NBCBAYAREA - msnbc.com Cliff-Notes version: The unknown is whether the other gas utilities (SoCal Edison, EBMUD, etc.) will be subject to the same order.