Call before you dig????
I was doing concrete footers for some commercial playground equipment. Big hole requirements (like 4feet deep, 4 feet square = 64 cubic feet of concrete per footing)
Anyway, dig people marked phone, electric, etc. property used propane for heat, local propane co didnt come out, they just told us over the phone where the line was. They read it right off the plans. (right angle off the tank to side of building, right turn, 20 feet, etc.)
Digging was by hand with assistance of a two man auger.
Well, we found a burried electric line that had been abandoned thank God, it was no longer live. We then hit a 24 pair buried telco line about 6 feet away from where it was marked. Moved to next hole and hit the propane line about 15 feet from where it was supposed to be. All in the course of a couple hours.
The propane line wasnt damaged, just bent a little. We had it checked by the propane co at their expense anyway. The telco line was on the phone co side of the NID so no cost there either.
The telco just made the repair in the hole, no new line. They used some splicing stuff made for direct burial. I'll bet the same exists for electrical.