The first 2 pictures are the plumber locating the water line. The last picture is a fancy device that helps spot water leaks or that is what he claims it was (looks like headphones and a weight on a roap). You walk in a line with the device and then walk in circles around the building’s concrete foundation. Seriously though you can guess where the leak is: it is under the building’s concrete foundation. The plumber was saying that the water line is so deep that he guesses he would have to rip out a huge area outside and inside the equipment room. Fun.
So the plan is to run a new water line and forget about the crappy copper line.