Transformer PCBs
    Topic posted April 10, 2009 by Dutch74Super Contributor, last edited January 19, 2012 
    4490 Views, 30 Comments
    Transformer PCBs

    I am doing a Phase I on a site which has numerous power transformers on the site.  There isn't any information physically posted on the transformers themselves, and the power company has been unable to find records on these.

    In your opinion , would these be an REC based on possible presence of PCBs?  There is vegetation near the base.



    • McCarthy
      Would be nice to have the blue "No PCBs" label.  However, if there is no staining of the pad or stressed vegetation around the pad, I would go w/ de minimis.
    • jessedphillips

      I agree; the transformers do not constitute a REC based on the ASTM standard definition. 

      Normally, I'd try to get the utility company to say something like "The equipment in our distribution system conforms to all applicable environmental laws and regulations and we plan to retain that equipment in service for the remainder of its useful life.  The transformers located at the subject property were manufactured prior to 02 July 1979, have not been tested, and must be assumed to be PCB-contaminated, per EPA regulations.  In the event of an oil spill or leak from any of its electrical equipment, our company will clean up and recover the oil released in accordance with all applicable federal, state, and local guidelines."

      This quote was adapted from something that I did get a power company to provide.  It was pretty generic, and now, whenever I encounter equipment owned by the company on a site, I throw this in the report, and attach the original letter in an appendix. 

      Ultimately, the owner of the equipment is going to be responsible for its maintenance/upkeep (unless there is some kind of agreement).  Go with de minimis, and say that, if there is an issue, the owner is responsible. 


    • LSchnapf
      The TSCA regulations provide that if a transformer does not have any marking, it is assumed to contain PCBs. That being said, without evidence of a release, there would be no REC. Howeverm failure to mark PCB-containing transformer would be a TSCA violation. This could be flagged as an additional environmental condition or concern but not a REC.  
    • pburgess
      Would depend somewhat on how old the transformers are. If they are old, they could have leaked years ago and staining may not still be present. Also, transformers can have oil without PCBs, and that would still be an issue if they leaked.
      • tryoncw
        Good point pburgess. Evaluation of the potential for an historical release is too often based solely on direct evidence of a release. Consideration of the duration and era of operations also come into play.
    • McCarthy

      Based on the other fellows questions, I guess I would have to ask what type of site it is if there are "numerous power transformers on the site"?  What did they need multiple transformers for?  The presence of the transformers may be more suggestive of heavy industrial electrical use and mulitple operational areas related to RECs than the actual transformers themselves.  I'm assuming this isn't a large vacant chain link fenced industrial site with nothing left but transformers.

    • Tom Speight

      Are we talking about the smaller pole-mounted type, or the bigger pad-mounted type?

    • MaxEng

      I've read lots of comments with respect to PCBs and "no signs of release."  What signs of release are you talking about?  Typically PCBs are colorless, and I've seen screaming high levels (i.e., 1000 ppm) of PCBs on concrete pads with no staining or other visual evidence.  Conversely, I've tested heavily stained pads under documented PCB fluid-containing equipment, with non-detect PCB analysis.  (Staining was a result of leaks or spills of petroleum fluids that may have predated the PCB use, or may have been unrelated to transformer operations.)

      PCBs are a can of worms, because once you find them, USEPA will claim you have to do all sorts of things under TSCA.  But irony of ironies, it's not clear that USEPA really has any enforcement power under TSCA unless you're the one who actually caused a release. 

      PCBs have a way of completely derailing brownfield cleanups.  I'd be highly pleased to see TSCA sink into the sea (from a real-estate transfer standpoint), since the health risks associated with PCBs really don't warrant doing all the expensive things that the "self-implementing cleanup" rules require.  They're just another group of chemicals whose risks can be managed and abated no differently from any other chemicals.


      (Rant over now.)

    • jessedphillips

      This seems to be an appropriate topic thread to ask present this problem:

      I am getting a proposal together to perform some soil borings around a pad-mounted transformer that may or may not have leaked over the last 35-40 years when it's been sitting there.  I don't know if the original fluid has been replaced and have no idea regarding the maintenance of the unit. 

      So, besides PCBs and mineral oil, which analyses would be appropriate?  My understanding is that silicone based or Fluorinated Hydrocarbons, naphthalenic mineral oil, and other things are currently or have been used as transformer fluid; however, I'm not sure whether there are analyses that catch these constituents. 

      Thanks for any help!

    • McCarthy

      Have never sampled for anything but the straight aroclor suite for transformers.  I have to ask..."may or may not have leaked"?  Why sample if there are not signs of leaking, such as oil-stained concrete?  I've never heard of sampling near pole-mounted or pad-mounted transformers in the absence of obvious staining?

    • Patrick Sutton

      MaxEng addresses that point above.  PCBs are colorless, so there may not be visible evidence of a release. 

    • jessedphillips

      We are sampling because the client is very proactive/conservative.  No Phase I has been completed; the facility is retrofitting their electrical system which includes the repplacement of the existing transformer (which they own).    The client wants to have soil borings conducted beforehand to get an idea of what they may encounter. 

      They may, upon seeing the proposed cost, just "wait and see" following the removal of the transformer and the concrete slab.  With PCBs being colorless, would there be any other visible evidence?  There is no vegetation; the transformer is along a concrete loading area on a concrete lot. 

      After talking to a couple of labs, I'm thinking that running oil range organics (ORO) will identify the presence of oil, and running PCBs will tell if it is PCB contaminated.  Any thoughts?

      • Tom Speight

        PCBs aren't necessarily colorless; some blends are yellowish or light green.

        In most of my experience with transformers, I've found more problems where the contamination isn't obvious than where it is-- weeping lines or casings rather than blowouts.  People generally notice the blowouts.

        I usually run a petroleum method in conjunction with SW846 Method 8082 for lab methods-- that covers most of the bases (even if the PCB level is less than the action threshold, the TPH might be over). The Dexil Clor N Soil kit is decent for field-screening on a yes/no basis for >50ppm, but the minimum detection limit is way more than the 1ppm cleanup threshold TSCA and some other regulations require.

        Just as general advice, remember that any porous material the PCBs may have come into contact with should also be evaluated.  I've seen bricks that had soaked up ~40,000 mg/Kg of PCBs.

        • McCarthy

          Your comment seems to suggest that any site that has had a transformer prior the switch to non-PCBs alternatives (i.e. most developed properties on the planet) may have had significant, unnoticed historic releases of oils containing PCBs.  Is this the message and do you consequently advise almost all clients to conduct soil sampling below pole-mounted and wipe samples on all pad-mounted transformers?  If this isn't your recommendation, what is it?

    • McCarthy

      Are you suggesting that only the colorless PCBs would leak from the transformers without the colorful oil in which they're entrained at only a low percentage?  That would be a pretty impressive osmotic event. 

    • jessedphillips

      I thought the carrier oil would be visible (I haven't seen dielectric fluid and thought, based on above comments, that it too may be colorless). That makes me feel better.  Also, I like the wording...impressive osmotic event. Ha.

    • Patrick Sutton

      I had a site where an old transformer had been dumped and clear fluid leaked into the soil.  The soil sample confirmed the presence of PCBs.  I know very little about the fluids used in transformers.  Have other people found PCB-containing oil to be colorless or dark?    

      • MaxEng

        Actually, I believe the pure PCB dielectric fluid was usually colorless; it was when the mixtures arose (due to incomplete flushing, etc.) that you found the fluid taking on coloration from the non-PCB replacement.  Or so my distant memory suggests ...

    • McCarthy

      I recently did a walk-through where there was dark staining on the pad under some large 80-year old transformers.  I don't know if the oil was originally dark, but even if it were originally colorless I would suggest that it wouldn't take long for standing oil to accumulate dust and other airborne particulates to color it up.  Where I've seen pole-mounted transformer leaks to the soil, typically you're seeing a sheen or gloss or darker coloration than the surrounding soils.