NEW YORK (AP) — Can a machine that dispenses water for free also turn into a cash stream for Coca-Cola?

The world's largest soda maker is testing a fountain that lets people fill reusable water bottles with free, filtered water — but also offers the option of paying to add bubbles and fruity flavors. It's an example of how the maker of Fanta, Sprite and Powerade is searching for new ways to make money as Americans cut back on traditional sodas.

For now, Coca-Cola is testing just one "Dasani Purefill" machine on the campus of Georgia Tech, across the street from its headquarters in Atlanta. It...