demolition of 60 year old liquid filled transformer

mshields

Senior Member
This 34.5kV to 4160V transformer had it's dielectric changed out to non-pcb many years ago. The client, having gotten 60 years out of it has finally decided to get rid of it. Should I be worried about PCB's that might have seeped into parts of the interior of the transformer. i.e. might the thing still be considered to be contaminated and what should my specifications say to cover that which might need to be done?

Thanks,

Mike
 

petersonra

Senior Member
This 34.5kV to 4160V transformer had it's dielectric changed out to non-pcb many years ago. The client, having gotten 60 years out of it has finally decided to get rid of it. Should I be worried about PCB's that might have seeped into parts of the interior of the transformer. i.e. might the thing still be considered to be contaminated and what should my specifications say to cover that which might need to be done?

Thanks,

Mike
how about just telling the demolition contractor it used to have PCBs in it and to take appropriate measures.
 

templdl

Senior Member
There should be a sampling valve and as such take a sample and have it analyzed for PCBs. The oil itselve most likely is a mineral oil similar to shell diala.
 

GoldDigger

Moderator
Staff member
There should be a sampling valve and as such take a sample and have it analyzed for PCBs. The oil itselve most likely is a mineral oil similar to shell diala.
Gambling:
1. Quote from contractor for demo work based on uncertainty about oil status.
2. Quote from contractor for demo work based on tested clean oil.
3. Quote from contractor for demo work based on tested contaminated oil.

If you and the contractor both evaluate the odds that the oil is contaminated in the same way, then 1 versus (2 or 3) should be a wash except for the cost of testing. :)
 

templdl

Senior Member
Gambling:
1. Quote from contractor for demo work based on uncertainty about oil status.
2. Quote from contractor for demo work based on tested clean oil.
3. Quote from contractor for demo work based on tested contaminated oil.

If you and the contractor both evaluate the odds that the oil is contaminated in the same way, then 1 versus (2 or 3) should be a wash except for the cost of testing. :)
It appears as though you have had experience with the cost of disposing of oil tainted with PCBs and untainted and the cost of doing so. As such I am of the understanding that you are saying that the cost disposal is about the same for both.
 

GoldDigger

Moderator
Staff member
It appears as though you have had experience with the cost of disposing of oil tainted with PCBs and untainted and the cost of doing so. As such I am of the understanding that you are saying that the cost disposal is about the same for both.
Not at all. What I was trying to say was that if the contractor thinks that there is a 50% chance that the oil is contaminated, he will quote you an amount halfway between the two costs.
If you think it is more like a 10% chance, you will pay for the test and hope to get off cheap.
If you think the odds are more than 90% for contaminated, you will avoid. finding out and take the contractor's risk-based bidiwfy instead.
 

weressl

Esteemed Member
This 34.5kV to 4160V transformer had it's dielectric changed out to non-pcb many years ago. The client, having gotten 60 years out of it has finally decided to get rid of it. Should I be worried about PCB's that might have seeped into parts of the interior of the transformer. i.e. might the thing still be considered to be contaminated and what should my specifications say to cover that which might need to be done?

Thanks,

Mike
Read the EPA rules. They are specific as to what to do with transformers that are reclaimed. If the replacement was done properly there were specific rules of monitoring after the initial change and testing for the success of replacement. There were also rules for disposal. The original company who had done the fluid replacement would probably well versed in these rules.
 

templdl

Senior Member
Not at all. What I was trying to say was that if the contractor thinks that there is a 50% chance that the oil is contaminated, he will quote you an amount halfway between the two costs.
If you think it is more like a 10% chance, you will pay for the test and hope to get off cheap.
If you think the odds are more than 90% for contaminated, you will avoid. finding out and take the contractor's risk-based bidiwfy instead.
I was trying to follow the logic of your thinking. As
 

steve66

Senior Member
Not at all. What I was trying to say was that if the contractor thinks that there is a 50% chance that the oil is contaminated, he will quote you an amount halfway between the two costs.
If you think it is more like a 10% chance, you will pay for the test and hope to get off cheap.
If you think the odds are more than 90% for contaminated, you will avoid. finding out and take the contractor's risk-based bidiwfy instead.
Not trying to side track the thread, but in my experience, if there is a 1% chance of something more expensive happening, the contractor will either:

1. Play it safe and quote full cost of worst case. (If the worst case doesn't happen, the contractor just makes more money off the job.)
2. Not cover a worst case scenerio in the bid. They are then more likely to get the job. Then, when and if the worst case happens, the contractor will claim it wasn't in their bid. Then it will cost even more as a change order.
 

templdl

Senior Member
Not trying to side track the thread, but in my experience, if there is a 1% chance of something more expensive happening, the contractor will either:

1. Play it safe and quote full cost of worst case. (If the worst case doesn't happen, the contractor just makes more money off the job.)
2. Not cover a worst case scenerio in the bid. They are then more likely to get the job. Then, when and if the worst case happens, the contractor will claim it wasn't in their bid. Then it will cost even more as a change order.
Bingo! It's always best to know what trouble your going to get into before you do of at all possible.
 

Phil Corso

Senior Member
MShiels ... sorry, but Steve66's 1% won't cut it!

PCB's are quite miscible wth any oils! If contamination level is 5-ppm or more, then EPA considers it hazardous waste! And, believe me you don't want to do battle with the EPA!

If you need specific Do's and Don'ts, us know!

Regards, Phil Corso
 
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GoldDigger

Moderator
Staff member
MShiels ... sorry, but Steve66's 1% won't cut it!

PCB's are quite miscible wth any oils! If contamination level is 5-ppm or more, then EPA considers it hazardous waste! And, believe me you don't want to do battle with the EPA!

If you need specific Do's and Don'ts, us know!

Regards, Phil Corso
As always, knowledge trumps speculation!
Even if they "washed" the transformer several times when making the oil change (which I doubt they did), I cannot see any way that it would end up below a 5ppm threshold.
And considered homeopathically, that 5ppm would be incredibly strong compared to pure PCB. :roll:
 

weressl

Esteemed Member
As always, knowledge trumps speculation!
Even if they "washed" the transformer several times when making the oil change (which I doubt they did), I cannot see any way that it would end up below a 5ppm threshold.
And considered homeopathically, that 5ppm would be incredibly strong compared to pure PCB. :roll:
Not quite so. Remedial companies had processes that would assure that after the initial refill the 'leaching' of PCB's were monitored and coud NOT attach the PCB-free label until the proscribed and agreed upon - by EPA - time period had passed. It was quite arduous process. Nobody else but an approved remediator could legally touch any PCB filled or PCB-contaminated equipment. Each company - except Utilities - were legally obliged to test their liquid filled equipment and label it as either PCB-free, PCB-Contaminated or PCB-filled. If they choose not to test it, the equipment had to be labeled as PCB-filled and depending on its location, mainly concerning public exposure, they may had a time-table to remedy the situation, eg. get rid of it or decontaminate it.
 

templdl

Senior Member
Not quite so. Remedial companies had processes that would assure that after the initial refill the 'leaching' of PCB's were monitored and coud NOT attach the PCB-free label until the proscribed and agreed upon - by EPA - time period had passed. It was quite arduous process. Nobody else but an approved remediator could legally touch any PCB filled or PCB-contaminated equipment. Each company - except Utilities - were legally obliged to test their liquid filled equipment and label it as either PCB-free, PCB-Contaminated or PCB-filled. If they choose not to test it, the equipment had to be labeled as PCB-filled and depending on its location, mainly concerning public exposure, they may had a time-table to remedy the situation, eg. get rid of it or decontaminate it.
These were my thoughts when I recommended previously to take a sample of the liquid before you do anything else and get it analized.
I once shared an office with engineering service which did liquid changeouts and became familiar enough with their procedures when doing PCB change outs and learned to respect the process.
As such I appreciate your expert input into this subject as it is the procedure as I recall.
 
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