In article ,
micky wrote:

Do copper or copper-clad steel ground rods disappear with time?

After 37 years, does mine need replacing?

When I put in my first burglar alarm, 37 years ago, I put in a ground
rod to ground the system, and iiuc reduce the chance of lightening
damage. (Nonetheless, after about 20 years, when I was leaving for
work, there were wisps of smoke coming from the keypad/control usit, and
it never worked again. ;-) I have a new alarm now, grounded to the same
rod, but something told me the rod was gone. The top of it is still
there so maybe I dreamed it, but is it likely that the part above ground
is there but most of it below ground is gone, and needs replacing?

My house was built in 1965, rewired in 2000. I recently found that
there was a new ground rod, but the old one is still there.

I have been unable to remove the old one. It is as if it had "rusted in
place". I even tried using an old bumper jack and chain to raise it.
It wouldn't budge, but the chain broke!

This does not answer the question of whether it is still a good ground.
Unless you have a way to test the old one, I recommend a new one.

Fred