I have a electrical/ plumbing business, and my plumber has a job in which he had to replace a main water line due to a leak. the problem is that it had been replaced 5 times prior in the past two years. The water department says that it is due to electrolosis and that the water line ground from the service should be removed. When he made the repair we checked voltage at the water meter and got around .3 volts. We have since replaced the service, and after 2 weeks the water line was leaking again. Has anyone ever heard of this or have any answers. Thanks.