No, you cannot. Don’t even dare! My dog got sick when I was living in Puerto Vallarta. When I brought her to the vet, she told me that I have to change their drinking water to mineral water. If a dog can get sick from drinking tap water in Puerto Vallarta, imagine what that can do to you! Restaurants usually have free “house water” but they are mineral water, I assure you. When in doubt, always order bottled water. You know yourself better than anyone! Some foreigners also ask me what water they use when they wash vegetables in Mexico but I really can’t give any information about this because I wash my vegetables with tap water. I use microdyn with the water and so far, I haven’t been sick. I can’t speak for the restaurants but I am sure they are doing the same. Microdyn is kind of a thing in Mexico – every household has it.