-inject dye in one well and observe where dye appears in other wells
-determines velocity and direction of groundwater flow
-carbon - 14 can date groundwater at various wells
-determines how long since water entered groundwater system
The correct answer is Aquafier. I just took the test and it was the correct answer. :)
Water that reaches Earth as precipitation becomes groundwater. If that groundwater moves through the unsaturated soil zone into the saturated zone, it becomes part of an aquifer.