Got a call to check out a situation where this new house (3 years old) has one shower that has a blue ring on the bottom of the tub and the faucet/drain are tarnished blue. There are five bathrooms in this house and only one bathroom has this problem. It is also the last bathroom on the water pipeline (yes, all copper).
From what the owner has told me, he has called one plumber and two electricians before me and the problem still has not been solved (I don't know what has been done yet). The plumber told him that this bathroom was receiving some stray voltage that reacts with the copper piping, thus turning the particular minerals in his water blue. I have not been to the house yet to inspect the main panelboard or any of the bonding techniques, but am going over there tonight.
Have any of you run into this? From what I understand, a grounding ring was suggested, but this house has two large cement driveways and a large underground network of irrigation piping which would make this solution quite labor-intensive. Any help would be greatly appreciated. Thanks!