Oh my look at those eyes, look at the trouble that they hide inside. See the flicker of pain on the rise. Oh my look at those eyes. Maybe they're like mine, things I wish I did not see. Push away all the dirt and debris, what will be left of me? -- Alexz Johnson, Look at Those Eyes
So they purified the water by adding minerals in order to give the water an enhanced flavor. Because normal water is neither pure enough nor has it sufficient flavor.