It's easy to take safe drinking water for granted, but so very much of public health stems from having it (that is, having lots of it) on hand. Moreoever, the problems that've recently affected Flint, Michigan -- and other communities -- have brought the whole potable-water issue to the forefront for many Americans. Where does Tulsa's drinking water come from, and how does it get here? How safe is it, and how clean or "pure" is it? And how do we know these things? How is our water monitored? And how often?