The drinking water here in Santiago, Chile comes from the Andes mountains. The water is hard with a high mineral content. When we wash eating utensils, if spoons are left laying flat to dry, cup up, there will be an opaque white film in the cup of the spoon when it dries.
Shortly after arriving here, we learned from some other gringos that kidney stones are common here among gringos. Our bodies are not accustomed to handling the high mineral content of the water. So, we consider the Brita filter a necessity for us here. So far, we haven't had any problems. It seems to be serving us well.