These oil filled transformers, would they by any chance
have PCBs in them? I seem to remember they used to.
depends how old, not sure what dialetric they use now.
No, they have all been converted to non-PCB oils.
Besides large transformers will have a concrete barrier container to capture all spillage.
Years ago - from 1929 to 1977 - they did; now they’re using mineral oil derivatives:
http://en.wikipedia.org/wiki/Transformer_oil#Current_mineral_oil_alternatives
All of the PCB has been removed from everything possible, and re-refined to use in making refrigerants.
There was an episode of Doomsday Preppers where one of the preppers plans after the apocalypse was to shoot the bottoms of transformers to collect the mineral oil. He did this and then threw a tarp down and collected some of the oil.