I am currently running electrical service to a new space in a mobile home park. This place has, supposedly, never had a mobile home in it before.

My first hint that this might moy be s completely 'new' space came when a large tree was removed from next to the power pole. Voila! - an old mast / weatherhead was found arrached to the power company's pole.

Yesterday, while trenching to the new trailer, I (naturally) ran dead-center into a buried ground rod. This ground rod - and I do mean a proper ground rod of copper jacketed steel with an acorn clamp - is only 3/8" diameter. I have no idea as to the length. I'm not sure if there is a stub of wire still attached; if there is, I doubt it's larger than #12.

My questions are: when were such rods allowed? How large a service? Why were they discontinued?