Our pump was about 30 years old when it failed. It cost about $1,500 to
pull it out and replace it. The first sign of failure was "crap" that
clogged up filters. Just before it failed the water has some oil in it.

You don't want to wait for a complete failure and you don't want to
contaminate your plumbing with the oil.problem?

Thirty year old oil filled motor used for a well?

PCB's ?.......Did they use to use PCB's in well pumps?
My guess is they did. Way back when PCB's were not
recognized as being dangerous it was a common oil
to cool and lubricate motors.

I wonder how many wells and or water sources have
been contaminated?