Groundwater in Jefferson County, Tenn., occurs in solution openings that follow bedding planes and strike joints in the dense limestone and dolomite. Recharge beginning at topographic highs in the northwest moves across strike to lows in the southeast; it is intercepted and collected by high permeability beds in the middle of the Knox Group and is routed along strike to discharge at large springs. Exploratory wells were drilled at two sites to test this concept of the flow system. Three wells at Moore Spring site in the recharge area penetrated only mud and solid rock. Four wells at Riley Spring site in the discharge area each penetrated at least five water-bearing openings that gave these wells an average production of 93 gallons per minute and a maximum of 180 gallons per minute. (USGS)