The leak was coming from a half inch hot waterline. I shut the water off to the building, and drain the water distribution system. After draining the water distribution system, I proceeded to repair the pinhole leak. After the repair the water distribution system was pressurized. Tested for leaks. My professional recommendation is to re-pipe the entire water distribution system of potable water because multiple repairs have been made with evidence to show, and the material used for the piping is recalled.