EMF NIMBY

[P-E]

So the local utility is proposing to route 1.5 miles of 345 kV cable in underground concrete duct bank through our town.   Residents are moving to block the project based on health concerns due to EMF and the inconvenience of digging up roads. 

I'm guessing that there isn't anything to be worried about.  Any thoughts?

 

[matt267 PE]

nothing to worry about

 

[mudpuppy]

Holy crap, underground 345 kV?  $$$$$$$$

 

[Supe]

It may create some interference from the alien signals.  I know it may sound crazy, but you may need to double or triple your tinfoil hats.

 

[knight1fox3]

So the local utility is proposing to route 1.5 miles of 345 kV cable in underground concrete duct bank through our town.   Residents are moving to block the project based on health concerns due to EMF and the inconvenience of digging up roads. 

I'm guessing that there isn't anything to be worried about.  Any thoughts?

Nothing based on any concrete evidence (see what I did there?).  But honestly, most of the "reports" I've reviewed are mostly speculation and due to other environmental factors.  The underground installation will be more disruptive to the physical area but will be more stable and protected long-term.  And once it is installed, people are quick to forget versus being reminded with overhead installations.

Holy crap, underground 345 kV?  $$$$$$$$

What's so special about that?  I've worked on projects that installed 500 and 765kV lines. :dunno:

 

[Dexman PE PMP]

 

[mudpuppy]

Nothing based on any concrete evidence (see what I did there?).  But honestly, most of the "reports" I've reviewed are mostly speculation and due to other environmental factors.  The underground installation will be more disruptive to the physical area but will be more stable and protected long-term.  And once it is installed, people are quick to forget versus being reminded with overhead installations.

What's so special about that?  I've worked on projects that installed 500 and 765kV lines. :dunno:

Good grief.  For comparison, we put 345 kV on wood poles to save money.

 

[Flyer_PE]

Expensive as all hell.  Any EMF will be absorbed by the surrounding earth. 

 

[knight1fox3]

Any EMF will be absorbed by the surrounding earth. 

Curious as to what you may have come across with regard to over-head lines by comparison.

 

[Flyer_PE]

To me, it's simple physics.  Mathematically, the vector sum of the three phases will be 0.  The overhead lines will mess with an AM radio signal but not much else.  The only reason they do that is that the conductors are spaced so far apart and above ground.  For an overhead installation, the air between the lines and earth beneath them IS the insulation.  You put the conductors closer together and put a layer of grounded material between you and the line and pretty much all detectible energy will be absorbed.

 

[Dexman PE PMP]

We had to re-route part of our lightrail system around a medical campus because they were concerned the vibration from the train and the EMF from our 700V overhead power system would disrupt their sensitive research equipment.  They weren't sure it would be a problem, but they were working on several major grants and bringing in several new researchers and didn't even want the perception of the effects to be a problem.

 

[knight1fox3]

To me, it's simple physics.  Mathematically, the vector sum of the three phases will be 0.  

Agreed.  Assuming the system in question is perfectly balanced.  Which is not always the case, hence the random speculation.

I'd be more concerned with living near a substation/switch yard (with regard to noise/vibration) than I would be with over-head HV conductors.

 

[Flyer_PE]

Agreed.  Assuming the system in question is perfectly balanced.  Which is not always the case, hence the random speculation.

I'd be more concerned with living near a substation/switch yard (with regard to noise/vibration) than I would be with over-head HV conductors.

HV transmission is typically delta.  Even if they aren't balanced, the sum will still be 0.

 

[mudpuppy]

We had to re-route part of our lightrail system around a medical campus because they were concerned the vibration from the train and the EMF from our 700V overhead power system would disrupt their sensitive research equipment.  They weren't sure it would be a problem, but they were working on several major grants and bringing in several new researchers and didn't even want the perception of the effects to be a problem.

Rolling my eyes at that one.  The medical campus probably has 480 V (or higher) running right through the buildings and they think 700 V outside is going to make any difference?  Heck, they probably have an MRI machine that creates waaaaaay more EMF than any of the above.

 

[Flyer_PE]

Rolling my eyes at that one.  The medical campus probably has 480 V (or higher) running right through the buildings and they think 700 V outside is going to make any difference?  Heck, they probably have an MRI machine that creates waaaaaay more EMF than any of the above.

On top to fhat, I suspect that 700V is DC.  Not even an alternating field.

 

[Dexman PE PMP]

They are looking to build new facilities along that road that would be used for research and wouldn't be near the main hospital with the above amenities. We honestly preferred re-routing the line because the ROW costs to run it through the campus were insanely higher than the new route around the campus.  We only suggested going through for convenience for the hospitals' visitors & staff.

 

[Road Guy]

If I was still in my County Engineer job I would stay I don't care just keep it off my GD ROW

 

[Dexman PE PMP]

Funny part is that most of our IGA's give us almost free access to any government ROW in the area.  On the west line we took one road from the city and turned it entirely into lightrail guideway.

 

[Road Guy]

That wont fly in Weld County

 

[Dexman PE PMP]

I know, because Weld County isn't part of our tax district.