As of December, there were seven fully functioning drinking water systems with 21 operating wells in Florida. Basically, the bubble is created by displacing the natural brackish water. Injected water will move radially away from the well and, since ground water flow velocity is generally slow, the injected water remains adjacent to the well for quite some time. The storage bubble in a typical well remains within 500 to 1,500 feet of the well. Zones in the aquifer that may be extremely permeable are avoided.
Current law requires the water to be disinfected before storage and again when it is retrieved.
The concern is that coliform bacteria that might be present in the water would contaminate the aquifer. But no water would be injected in areas used for public water supply. In any case, state health officials say the bacteria cannot live underground and pose no threat to the aquifer. The water underground will be monitored constantly for any degradation of quality. If water ever is retrieved for human consumption, it would be given all the treatment necessary for drinking water.