Recently I did a site survey at a local 20-year-old hotel. The internal copper water pipes are eroding away for some reason. The punch list above includes potential causes. This erosion will not fix itself. If the root cause cannot be identified, then an internal pipe coating injection system on main water line maybe required. Nothing maybe required, short of replacing leaky pipes, if the root problem is stray voltage that has inadvertently been corrected in the recent past.