Mark Cramer...you make good sense...it is VERY common, and this "stray" earth current is ONE explanation. However, on more than a few occasions, I (& Seller's electrician in one instance), noted the current, then disconnected the panel ground, and voila!...no more current to the water pipe. None,..zippola. But like you say, other times current remains, so must be coming from the earth. Doug...I too apologize for the other board comments, though I don't remember them. But knowing me, I most certainly contributed to the lack of humor. By the by, I use a SPERRY Model DSA 600 (digital readout).... & thanks for your input.