Where do you get your water from? That's way above what is legally allowed in any jurisdiction. It's actually harmful to health at that level and like someone is adding cautic soda to the water. The calcium carbonate some municipalities add to water to keep the pH above 7 couldn't get the pH that high even if it was way overdosed. I'd be checking your pH pen.
If supply water is below pH 7 cities etc add things like calcium carbonate to it to get it over 7 to protect the pipes and the biofilm that coats them. The screwup that happened in Flint was changing water to an acid one that wiped out the biofilm and let more than lead get leached from the old cast iron pipes in their system.