City water systems today are designed to stop metal leaching from the pipes to protect babies' tiny bellies. The way they do that is by immobilizing the cation exchange in water by adding two chemicals one being Sodium hypochlorite with a pH that is 11. The other chemical to bring the pH down called Sodium Bisulfite with a pH thats 3.6 to 4.6 and is used to lower the pH on outgoing water. Most tap waters are stripped of the positive and negative charge equilibrium with these two chemicals. That's not counting chlorine and chloramine designed to kill the microbes in the water on the way out. Tap water must be alkaline and "inactive" or it will leach metals.