Preliminary delineation and description of the regional aquifers of Tennessee: the East Tennessee aquifer system

The east Tennessee aquifer system occurs in the Valley and Ridge and the Blue Ridge provinces of Tennessee. These areas are underlain by rocks of Precambrian to Pennsylvanian age which have been structurally deformed and faulted during the Appalachian orogeny. Groundwater in the Valley and Ridge occurs primarily in solution openings in carbonate rocks and in fractures in sandstone and shale. Fractures in the crystalline rocks store and transmit most of the groundwater in the Blue Ridge province. The east Tennessee aquifer system is important as a source of rural and municipal drinking water. Within 300 ft of land surface, groundwater generally contains less than 500 milligrams/L dissolved solids. At greater depths, fractures and solution openings are smaller and fewer in number. There are very little data to define groundwater occurrence at depths greater than about 300 ft. Groundwater flow may be restricted and the dissolved solids concentrations in the groundwater may reach thousands or even ten thousands of milligrams/L.