24 replies to this topic

[ConcernedHDResident]

PG&E has decided to build a gas monitoring station in the historic district and is using eminent domain to acquire the property.  The project is real and moving forward, and the City has already agreed to a similar station outside of the historic district.  The purpose is to build a "pigging" input station near the old truss bridge, and the output station a few miles away. 

 

First of all, the use of eminent domain is very unfair to the owner of the property who does not want to sell, and risks property values for the neighborhood.  

 

Second, the residents of the HD are required to comply with design guidelines, and PG&E is exempt.  They can install an ugly station that is visible to all and negatively impacts the charm of the neighborhood, and may negatively affect property values as well.

 

Third, the reason for this is to test the high pressure gas main that runs up Bridge Street to the middle school, around the school and through Folsom. Will PG&E share test data with the City, and if so, how will the City communicate that information with residents?  

 

How is the City going to inform the community of the project and annual test results?

 

I hope the residents of the historic district are aware of what is under their streets, and that the community knows about the high pressure gas pipe that borders two sides of the middle school.  The pipes are old and have been re-pressurized.  Now PG&E is increasing monitoring and forcibly taking a neighbor's land.  If they are using eminent domain, then they should explain why they chose the location and not on the other side of the river where they can test the entire pipe, including the section that runs over Rainbow Bridge.  Seems to me that the old pipe on the  bridge is worth testing and that the City would want to protect the bridge as it is critical to traffic.  Just saying, why test only part of the line?

 

I attached a map of the gas line and two photos of the unattractive PIG station in San Lorenzo, CA.

 

 

Attached Files

•  PIG San Lorenzo ugly.jpg   60.63K   30 downloads
•  PG&E gas main.JPG   68.68K   32 downloads
•  PIG San Lorenzo Street View compressed.jpg   20.04K   26 downloads

[4thgenFolsomite]

Good questions!

[ducky]

All your questions are good ones.

 

Are you saying there will be a pigging station by the walking bridge as well?

If so, I'm not understanding why the output station wouldn't be at the end of the line instead of very near the input station or why the pig couldn't travel and then come back to the same station where it started.

 

Is PG&E trying to take the whole property where their house is located or only the portion for the station on a separate lot they own?

 

Added:  I looked at something on the smart pig device and it looks like it is something they can put in and remove without interrupting transmission.  Sounds kind of dangerous, but so does lines that aren't inspected or maintained.  I also couldn't find any documentation about the city negotiating with PG&E for another station.

[mrdavex]

If so, I'm not understanding why the output station wouldn't be at the end of the line instead of very near the input station or why the pig couldn't travel and then come back to the same station where it started.

 

Added:  I looked at something on the smart pig device and it looks like it is something they can put in and remove without interrupting transmission.  Sounds kind of dangerous, but so does lines that aren't inspected or maintained.  I also couldn't find any documentation about the city negotiating with PG&E for another station.

 

 

If a PIG is used in a pipeline that is actively delivering a product, it can travel in only one direction.  The PIG can't move on its own; it uses the pressure of the natural gas in the line to push it forward.  The map does not indicate which direction the gas travels, but assuming that it travels from South Folsom to North Folsom, that is why the PIG must be "launched" south of the river to be retrieved north of the river.  You are correct that a PIG will not interrupt the gas transmission, so it is relatively cheap and safe to use.

 

If you wanted to send the PIG back to the launching spot, you would have to completely shutoff the natural gas in that segment, bleed it off, and then somehow reverse the gas flow to flow from North to South.  Unfortunately, this would require interrupting natural gas servers to all customers downstream of the PIG station, which would be very undesirable.  

[ducky]

 

If a PIG is used in a pipeline that is actively delivering a product, it can travel in only one direction.  The PIG can't move on its own; it uses the pressure of the natural gas in the line to push it forward.  The map does not indicate which direction the gas travels, but assuming that it travels from South Folsom to North Folsom, that is why the PIG must be "launched" south of the river to be retrieved north of the river.  You are correct that a PIG will not interrupt the gas transmission, so it is relatively cheap and safe to use.

 

If you wanted to send the PIG back to the launching spot, you would have to completely shutoff the natural gas in that segment, bleed it off, and then somehow reverse the gas flow to flow from North to South.  Unfortunately, this would require interrupting natural gas servers to all customers downstream of the PIG station, which would be very undesirable.  

 

Thanks, once again, for the great explanation.  I think I was assuming the gas ran the other way.  If it is running from the Historic District towards Rainbow Bridge and on up Greenback, I think ConcernedHDResident has a valid question about the location.  There are probably a million other factors PG&E has to consider, but I'd like to know the reason for choosing that particular location. 

[maestro]

Concerned HD Resident,

there is another very real reason to be concerned about this device:

 

it generates a strong magnetic field which is known to cause harm. 

The device has a clear warning sign attached to it:

 

 

[mrdavex]

Concerned HD Resident,

there is another very real reason to be concerned about this device:

 

it generates a strong magnetic field which is known to cause harm. 

The device has a clear warning sign attached to it:

 

 

 

Thanks for the video; it was very informative.  But I've seen magnetic warning signs like that everywhere, like on microwave ovens.  Even a magnetic name badge I wear on my shirt has a warning not to be worn by persons with pacemakers, and it's no stronger than a refrigerator magnet.  

 

If that PIG's magnetic field were indeed strong enough to pose a public hazard, that engineer's wristwatch and forearm would have flown towards the magnet.  For comparison, here are some experiments showing how strong the magnetic field of an MRI device is:   

 

That's why they make sure you remove all jewelry before having an MRI.  

[maestro]

Thanks for the video; it was very informative.  But I've seen magnetic warning signs like that everywhere, like on microwave ovens.  Even a magnetic name badge I wear on my shirt has a warning not to be worn by persons with pacemakers, and it's no stronger than a refrigerator magnet.  

__________________________________________________________________________________

 

Love to know what you do for a living.    

 

Do you know even a weak EMF  can harm delicate tissues -- especially in babies and elderly.     The red warning sign is deadly serious for a person with any heart implanted device or artifact.      EMF can and absolutely DOES do harm to living tissue and electronic devices.

 

Impact of an EMF on the Piezo Crystals used in electronic devices like defibrillators, pacemakers, is extremely serious.     That red warning sign is no joke:   a heart device can malfunction or fail in the presence of even low EMF.      Death can result.   

 

SMUD experts can tell you even EMF from high voltage lines needs to be considered by those vulnerable.   That's why no one wants a house under the 160 to 230 KV lines in Folsom.     Because of cell phones popularity, the public does not wish to hear about EMF and cancers.   But that does not cancel the dangers.     

 

I still believe this HD resident is quite correct to be concerned about PG&E, because their negligence killed people in San Bruno and exploded dozens of homes.     Would you trust PG&E to warn you when a dangerous EMF is traveling under your feet, in the ground?    They also nearly doubled my gas bill to pay the damages they caused.

 

 

 

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[FolsomEJ]

Better Call Saul

[mrdavex]

I'm an Electrical & Computer Engineer, but am interested in all fields on engineering and the way things work.  However, electromagnetics is not my specialty, so I can't really speak too much about the dangers of EMF to human tissue.  All I can say is that an MRI magnet is way more powerful than the Smart PIG's magnet.  In that case, those who have health concerns about EMF should avoid having an MRI, although the alternative CT and PET scans expose the body to X-rays and Gamma-Rays, whichhave known carcinogenic effects for long-term exposure (http://www2.lbl.gov/...ec/EMSpec2.html)

I don't know what is the strength of the magnetic field on that PIG, but when placed inside a thick steel pipe that provides shielding, and with that pipe buried several feet underground further attenuating the field, I will venture to say that any resultant magnetic fields on the surface (if any) would be much weaker than Earth's magnetic field that were are exposed to every second of our entire lives.

 

With this said, though I do share you concern about PG&E's integrity, especially after the San Bruno explosion, but also the 2008 Rancho Cordova explosion, and the grounDwater contamination in Hinkley that was immortalized in Erin Brockovich.  If PG&E's pig does detect pipeline abnormalities, I would hope they share the findings with the public, and promptly make the necessary repairs. 

 

 

 

Love to know what you do for a living.    

 

I still believe this HD resident is quite correct to be concerned about PG&E, because their negligence killed people in San Bruno and exploded dozens of homes.     Would you trust PG&E to warn you when a dangerous EMF is traveling under your feet, in the ground?    They also nearly doubled my gas bill to pay the damages they caused.

 

 

 

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[mrdavex]

Here is an introduction to how the Smart PIG uses Magnetic Flux Leakage to detect defects in a steel pipeline:

 

http://www.mfeenterp...om/what-is-mfl/

 

These discussions cause me to learn something new every day!  

[maestro]

I'm an Electrical & Computer Engineer, but am interested in all fields on engineering and the way things work.  However, electromagnetics is not my specialty, so I can't really speak too much about the dangers of EMF to human tissue.  All I can say is that an MRI magnet is way more powerful than the Smart PIG's magnet.  In that case, those who have health concerns about EMF should avoid having an MRI, although the alternative CT and PET scans expose the body to X-rays and Gamma-Rays, whichhave known carcinogenic effects for long-term exposure (http://www2.lbl.gov/...ec/EMSpec2.html)

I don't know what is the strength of the magnetic field on that PIG, but when placed inside a thick steel pipe that provides shielding, and with that pipe buried several feet underground further attenuating the field, I will venture to say that any resultant magnetic fields on the surface (if any) would be much weaker than Earth's magnetic field that were are exposed to every second of our entire lives.

 

With this said, though I do share you concern about PG&E's integrity, especially after the San Bruno explosion, but also the 2008 Rancho Cordova explosion, and the grounDwater contamination in Hinkley that was immortalized in Erin Brockovich.  If PG&E's pig does detect pipeline abnormalities, I would hope they share the findings with the public, and promptly make the necessary repairs. 

 

 

 

 

Thanks for sharing the EE, CS eng. info.     Glad you are interested in learning more.

 

Just remember, the weakest (babies and elderly and those with implants) are very vulnerable to this field.    An MRI is 100% contraindicated for those with implants/replacements/devices.    

Devices CANNOT be near an auto engine, nor a microwave.    Medtronic Defib-PM maker has info.

 

Also, milliamps are enough to kill.   PG&E may tell you plenty about voltage, but current is another matter.     The metal pipes CONVEY the current, NOT insulate it -- 

hence PG&E  has the huge signage.      EMF is nearly totally unknown commodity:  better safe than dead, IMO.

 

Stay interested!   It's a good thing.

 

 

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[ducky]

PG&E was working all night at the corner of Wales and School Street last night.  Was there a gas leak or something?

[nomad]

PG&E was working all night at the corner of Wales and School Street last night.  Was there a gas leak or something?

 

Probably. Trying to prevent San Bruno part II. I also wonder what my rates will look like when that fat 1.6b fine is passed along to the customers.

[ducky]

 

Probably. Trying to prevent San Bruno part II. I also wonder what my rates will look like when that fat 1.6b fine is passed along to the customers.

 

That's what I was thinking or Rancho Cordova 2008.