Re: Current on waterpipe
BJ, the only reason neutral would be coming from the transformer would be if it is primary neutral taking a path through the house and water pipes to get back to the substation. Although this source is a suspect in the stray voltage controversy in rural farm areas, I do not think I have seen it in the residential work I have done.
You can find out with measurements. If all neutral is generated by load imbalances in the homes connected to this transformer and to this water system, you can measure at each service in the way I described, with a clamp-on ammeter.
Let's assume this just involves two residences. Open the main on your house. Measure the neutral amps (if it fluctuates during the measurement time you can use a meter that gives you the average).
As simultaneously as possible measure the neutral at your neighbor's service; the amount on the service neutral and the amount going to the pipe. Also measure the resultant of the hots by clamping around both at the same time. This resultant should equal the total neutral. If so, it shows that the neutral originated at that service. Do you get the idea? Currents always have to add up.
So I think it unlikely that you can pin this on the POCO. It is a NEC grounding requirement (which you are allowed to remedy). POCO is involved only in making sure their neutral connections are clean and tight.
Karl